Farm Exposures and Allergic Disease Among Children Living in a Rural Setting

OBJECTIVES

The purpose of this study was to examine the association between farm exposures and asthma and allergic disease in children while also highlighting the experiences of non-farm rural children.

METHODS

This was a cross-sectional analysis of data collected from across the province of Saskatchewan, Canada in 2014. Surveys were completed by parents of 2275 rural dwelling children (farm and non-farm) aged 0 to 17 years within 46 rural schools. Questionnaires were distributed through schools for parents to complete.

RESULTS

Asthma prevalence was 7.6%, of which 29.5% of cases were allergic. After adjustment for potential confounders, home location (farm vs non-farm) and other farm exposures were not associated with asthma and asthma phenotypes. Those who completed farm safety education were more likely to have asthma (11.7% vs. 6.7%; p = .001) compared to children without asthma. In sub-analyses among 6-12-year-old children, boys were more likely to have asthma (non-allergic) and use short-acting beta-agonists compared to girls. Doing farm work in the summer was associated with an increased risk of asthma [adjusted OR (aOR) = 1.71 (1.02-2.88); p = .041]. Doing routine chores with large animals was associated with an increased risk of asthma [aOR = 1.83 (1.07-3.15); p = .027] and allergic asthma [aOR = 2.37 (95%CI = 1.04-5.40); p = .04].

CONCLUSION

The present study showed that the prevalence of asthma and asthma phenotypes were similar between farm and non-farm rural children. There did not appear to be differential involvement in farming activities between those with and without asthma although those with asthma had more training suggesting possible attempts to mitigate harm from farm exposures.

OXGR1 is a candidate disease gene for human calcium oxalate nephrolithiasis

PURPOSE

Nephrolithiasis (NL) affects 1 in 11 individuals worldwide, leading to significant patient morbidity. NL is associated with nephrocalcinosis (NC), a risk factor for chronic kidney disease. Causative genetic variants are detected in 11% to 28% of NL and/or NC, suggesting that additional NL/NC-associated genetic loci await discovery. Therefore, we employed genomic approaches to discover novel genetic forms of NL/NC.

METHODS

Exome sequencing and directed sequencing of the OXGR1 locus were performed in a worldwide NL/NC cohort. Putatively deleterious, rare OXGR1 variants were functionally characterized.

RESULTS

Exome sequencing revealed a heterozygous OXGR1 missense variant (c.371T>G, p.L124R) cosegregating with calcium oxalate NL and/or NC disease in an autosomal dominant inheritance pattern within a multigenerational family with 5 affected individuals. OXGR1 encodes 2-oxoglutarate (α-ketoglutarate [AKG]) receptor 1 in the distal nephron. In response to its ligand AKG, OXGR1 stimulates the chloride-bicarbonate exchanger, pendrin, which also regulates transepithelial calcium transport in cortical connecting tubules. Strong amino acid conservation in orthologs and paralogs, severe in silico prediction scores, and extreme rarity in exome population databases suggested that the variant was deleterious. Interrogation of the OXGR1 locus in 1107 additional NL/NC families identified 5 additional deleterious dominant variants in 5 families with calcium oxalate NL/NC. Rare, potentially deleterious OXGR1 variants were enriched in patients with NL/NC compared with Exome Aggregation Consortium controls (χ2 = 7.117, P = .0076). Wild-type OXGR1-expressing Xenopus oocytes exhibited AKG-responsive Ca2+ uptake. Of 5 NL/NC-associated missense variants, 5 revealed impaired AKG-dependent Ca2+ uptake, demonstrating loss of function.

CONCLUSION

Rare, dominant loss-of-function OXGR1 variants are associated with recurrent calcium oxalate NL/NC disease.

Making white spots disappear! Do minimally invasive treatments improve incisor opacities in children with molar-incisor hypomineralisation?

BACKGROUND

Children with molar-incisor hypomineralisation (MIH) frequently seek aesthetic treatment for incisor opacities. Surprisingly, few studies have evaluated the clinical success of such interventions.

AIM

To quantify the effectiveness of minimally invasive treatments in reducing enamel opacity visibility in children with MIH.

DESIGN

This in vitro study used digital clinical images of 23 children aged 8-16 years with MIH who underwent microabrasion and/or resin infiltration for the management of incisor opacities. Standard images were taken pre-treatment and 6 months post-treatment. Image software (Image-Pro Plus^® V7) was employed to convert 24-bit RGB images to 16-bit greyscale and 145× magnification. Measurement repeatability was assessed using intra-class correlation coefficients (ICCs). Post-treatment changes in visible opacity area (mm² ) and brightness (greyscale value) were tested using the Wilcoxon signed-rank test for related samples.

RESULTS

The mean total opacity surface area significantly reduced from 14.3 mm² (SD = 7.5) to 9.4 mm² (SD = 9.0) post-treatment. The proportion of tooth surface affected by the opacity also significantly reduced from 22.5% (SD = 10.5) to 14.7% (SD = 12.7). The mean maximum opacity brightness significantly reduced from 53 066 greyscale value (SD = 4740) to 49 040 (SD = 3796). ICC was good/excellent (0.75-1.0).

CONCLUSION

Minimally invasive treatment is effective in reducing the size and brightness of discrete incisor opacities. Future research should compare objective findings with patient-reported outcomes.

A scoping review of the roles, training, and impact of community health workers in oral health

OBJECTIVE

To synthesize English or Spanish-language literature on community health workers' (CHWs') roles, training, and impact in oral health.

BASIC RESEARCH DESIGN

A scoping review conducted in accordance with the Arksey and O'Malley (2005) methodological framework.

METHOD

Electronic literature searches were conducted in Medline (Ovid), Embase (Ovid), DOSS, CINAHL, Web of Science, and Global Health CAB from inception of the databases to April 2020. Three reviewers independently conducted the title and abstract and full-text reviews. This was followed by data charting by three reviewers and data summarizing by two reviewers.

RESULTS

Out of the 36 articles that met the inclusion criteria, most took place in the United States (n=15) with most published between 2012 and 2019 (12). CHWs were incorporated in programs that focused on access to dental care (n=10), oral health promotion only (9), early childhood caries (8), oral health promotion and services (5), and oral cancer screening (4). Common roles included providing oral health education and behavior change motivation to community members, facilitating utilization of dental services, and the delivery of diagnostic and dental services to community members. Training and outcomes were not consistently described across studies.

CONCLUSION

CHWs have been used in oral health programs and interventions across a wide range of locations and contexts. The implementation and scaling-up of oral health CHW programs requires appropriate provision of training as well as community embedded monitoring and evaluation structures based on rigorous methods with clearly defined outcomes.

Divergent trends in the prevalence of asthma-like symptoms and asthma in a developing country: three repeated surveys between 2002 and 2016

INTRODUCTION AND OBJECTIVES

There have been differences in temporal trends of asthma prevalence by geographic region and economic prosperity. The aim of this study was to assess temporal trends in asthma prevalence among young adolescents in Skopje, Republic of North Macedonia as a developing country with a low asthma prevalence.

SUBJECTS AND METHODS

Data were obtained from three cross-sectional surveys (2002, 2006, and 2016) of adolescents (12-15 years) from randomly selected schools in Skopje. Trends in the prevalence of asthma and asthma-like symptoms were investigated descriptively and using multiple logistic regression to adjust for potential confounding factors.

RESULTS

The prevalence of asthma increased, although the changes were not statistically significant (2002: 1.7%; 2006: 2.0%; 2016: 2.8%; p=0.075). Statistically significant (p<0.05) reductions in wheeze prevalence over time (2002, 2006, 2016) were observed for current wheeze (8.8%, 7.2%, 5.5%), exercise-induced wheeze (14.2%, 7.9%, 1.9%), and night dry cough (16.5%, 13.5%, 9.6%). After adjustment for potential confounding factors, there was an increase in asthma likelihood by year compared to 2002 (2006: OR=1.22, 95%CI=0.67-2.22; 2016: OR=2.45, 95%CI=1.24-4.84). In the adjusted analyses, associations between year and the asthma-like symptoms confirmed the descriptive results, except for current wheeze, where statistical significance disappeared.

CONCLUSIONS

Divergent trends in prevalence with a decrease in asthma-like symptoms and an increase in physician-diagnosed asthma in Skopje during a period of 14 years were established. Improved asthma labelling and effective preventative treatment of symptoms may explain some of these changes, although changes in environment and lifestyle could not be ruled out.

Editor's Choice - Nationwide Analysis of Patients Undergoing Iliac Artery Aneurysm Repair in the Netherlands

OBJECTIVE

The new 2019 guideline of the European Society for Vascular Surgery (ESVS) recommends consideration for elective iliac artery aneurysm (eIAA) repair when the iliac diameter exceeds 3.5 cm, as opposed to 3.0 cm previously. The current study assessed diameters at time of eIAA repair and ruptured IAA (rIAA) repair and compared clinical outcomes after open surgical repair (OSR) and endovascular aneurysm repair (EVAR).

METHODS

This retrospective observational study used the nationwide Dutch Surgical Aneurysm Audit (DSAA) registry that includes all patients who undergo aorto-iliac aneurysm repair in the Netherlands. All patients who underwent primary IAA repair between 1 January 2014 and 1 January 2018 were included. Diameters at time of eIAA and rIAA repair were compared in a descriptive fashion. The anatomical location of the IAA was not registered in the registry. Patient characteristics and outcomes of OSR and EVAR were compared with appropriate statistical tests.

RESULTS

The DSAA registry comprised 974 patients who underwent IAA repair. A total of 851 patients were included after exclusion of patients undergoing revision surgery and patients with missing essential variables. eIAA repair was carried out in 713 patients, rIAA repair in 102, and symptomatic IAA repair in 36. OSR was performed in 205, EVAR in 618, and hybrid repairs and conversions in 28. The median maximum IAA diameter at the time of eIAA and rIAA repair was 43 (IQR 38-50) mm and 68 (IQR 58-85) mm, respectively. Mortality was 1.3% (95% CI 0.7-2.4) after eIAA repair and 25.5% (95% CI 18.0-34.7) after rIAA repair. Mortality was not significantly different between the OSR and EVAR subgroups. Elective OSR was associated with significantly more complications than EVAR (intra-operative: 9.8% vs. 3.6%, post-operative: 34.0% vs. 13.8%, respectively).

CONCLUSION

In the Netherlands, most eIAA repairs are performed at diameters larger than recommended by the ESVS guideline. These findings appear to support the recent increase in the threshold diameter for eIAA repair.

Panel sequencing distinguishes monogenic forms of nephritis from nephrosis in children

BACKGROUND

Alport syndrome (AS) and atypical hemolytic-uremic syndrome (aHUS) are rare forms of chronic kidney disease (CKD) that can lead to a severe decline of renal function. Steroid-resistant nephrotic syndrome (SRNS) is more common than AS and aHUS and causes 10% of childhood-onset CKD. In recent years, multiple monogenic causes of AS, aHUS and SRNS have been identified, but their relative prevalence has yet to be studied together in a typical pediatric cohort of children with proteinuria and hematuria. We hypothesized that identification of causative mutations by whole exome sequencing (WES) in known monogenic nephritis and nephrosis genes would allow distinguishing nephritis from nephrosis in a typical pediatric group of patients with both proteinuria and hematuria at any level.

METHODS

We therefore conducted an exon sequencing (WES) analysis for 11 AS, aHUS and thrombotic thrombocytopenic purpura-causing genes in an international cohort of 371 patients from 362 families presenting with both proteinuria and hematuria before age 25 years. In parallel, we conducted either WES or high-throughput exon sequencing for 23 SRNS-causing genes in all patients.

RESULTS

We detected pathogenic mutations in 18 of the 34 genes analyzed, leading to a molecular diagnosis in 14.1% of families (51 of 362). Disease-causing mutations were detected in 3 AS-causing genes (4.7%), 3 aHUS-causing genes (1.4%) and 12 NS-causing genes (8.0%). We observed a much higher mutation detection rate for monogenic forms of CKD in consanguineous families (35.7% versus 10.1%).

CONCLUSIONS

We present the first estimate of relative frequency of inherited AS, aHUS and NS in a typical pediatric cohort with proteinuria and hematuria. Important therapeutic and preventative measures may result from mutational analysis in individuals with proteinuria and hematuria.

What children say and clinicians hear: accounts relating to incisor hypomineralisation of cosmetic concern

AIM

To explore the range of impacts relating to incisor opacities as described by children, their general dental practitioners and paediatric dentists.

METHODS

Participants included 50 children, aged 7-16 years, referred to a UK hospital paediatric dentistry service for management of incisor opacities. All children were subsequently diagnosed with molar incisor hypomineralisation. Following ethical approval, data were recorded as follows: patient demographics, distance travelled, waiting times, nature of any impacts relating to incisor opacities documented in referral letters and/or in subsequent paediatric dentistry assessment records. Additionally, children completed the short form Child Oral Health Impact Profile questionnaire (COHIP-SF19) as a self-report measure of their oral health-related quality of life (OHRQoL).

RESULTS

Nearly, half (48%, n = 24) of the referral letters mentioned that the child was experiencing one or more negative social and/or functional impacts. Mean COHIP score was significantly lower (indicating poorer OHRQoL) for children whose referring dentist had identified a negative impact (COHIP = 42.9) compared to those with no documented impact (COHIP = 50.5; p = 0.018, independent t test). At the hospital consultation, negative impacts were elicited by a paediatric dentist in 86% (n = 43) of cases. Again, mean COHIP score was significantly lower for children whose assessment records noted a negative impact (COHIP = 44.5) compared to those with no recorded impact (COHIP = 60.2; p = 0.001). Families travelled a mean distance of 57 km (range 3-218 km) to the hospital service, with an average waiting time of 75 days from referral.

CONCLUSION

It is encouraging that dental professionals seem to be aware of the negative psychosocial impacts experienced by some children with enamel opacities, and that children feel able to describe them.

Eight-year follow-up of a randomized clinical trial comparing ultrasound-guided foam sclerotherapy with surgical stripping of the great saphenous vein

BACKGROUND

This was an 8-year follow-up of an RCT comparing ultrasound-guided foam sclerotherapy (UGFS) with high ligation and surgical stripping (HL/S) of the great saphenous vein (GSV).

METHODS

Patients were randomized to UGFS or HL/S of the GSV. The primary outcome was the recurrence of symptomatic GSV reflux. Secondary outcomes were patterns of reflux according to recurrent varices after surgery, Clinical Etiologic Anatomic Pathophysiologic (CEAP) classification, Venous Clinical Severity Score (VCSS) and EuroQol Five Dimensions (EQ-5D™) quality-of-life scores.

RESULTS

Of 430 patients originally randomized (230 UGFS, 200 HL/S), 227 (52·8 per cent; 123 UGFS, 103 HL/S) were available for analysis after 8 years. The proportion of patients free from symptomatic GSV reflux at 8 years was lower after UGFS than HL/S (55·1 versus 72·1 per cent; P = 0·024). The rate of absence of GSV reflux, irrespective of venous symptoms, at 8 years was 33·1 and 49·7 per cent respectively (P = 0·009). More saphenofemoral junction (SFJ) failure (65·8 versus 41·7 per cent; P = 0·001) and recurrent reflux in the above-knee GSV (72·5 versus 20·4 per cent; P = 0·001) was evident in the UGFS group. The VCSS was worse than preoperative scores in both groups after 8 years; CEAP classification and EQ-5D® scores were similar in the two groups.

CONCLUSION

Surgical stripping had a technically better outcome in terms of recurrence of GSV and SFJ reflux than UGFS in the long term. Long-term follow-up suggests significant clinical progression of venous disease measured by VCSS in both groups, but less after surgery. Registration number: NCT02304146 (http://www.clinicaltrials.gov).

Mutations in multiple components of the nuclear pore complex cause nephrotic syndrome

Steroid-resistant nephrotic syndrome (SRNS) almost invariably progresses to end-stage renal disease. Although more than 50 monogenic causes of SRNS have been described, a large proportion of SRNS remains unexplained. Recently, it was discovered that mutations of NUP93 and NUP205, encoding 2 proteins of the inner ring subunit of the nuclear pore complex (NPC), cause SRNS. Here, we describe mutations in genes encoding 4 components of the outer rings of the NPC, namely NUP107, NUP85, NUP133, and NUP160, in 13 families with SRNS. Using coimmunoprecipitation experiments, we showed that certain pathogenic alleles weakened the interaction between neighboring NPC subunits. We demonstrated that morpholino knockdown of nup107, nup85, or nup133 in Xenopus disrupted glomerulogenesis. Re-expression of WT mRNA, but not of mRNA reflecting mutations from SRNS patients, mitigated this phenotype. We furthermore found that CRISPR/Cas9 knockout of NUP107, NUP85, or NUP133 in podocytes activated Cdc42, an important effector of SRNS pathogenesis. CRISPR/Cas9 knockout of nup107 or nup85 in zebrafish caused developmental anomalies and early lethality. In contrast, an in-frame mutation of nup107 did not affect survival, thus mimicking the allelic effects seen in humans. In conclusion, we discovered here that mutations in 4 genes encoding components of the outer ring subunits of the NPC cause SRNS and thereby provide further evidence that specific hypomorphic mutations in these essential genes cause a distinct, organ-specific phenotype.

Whole Exome Sequencing Reveals a Monogenic Cause of Disease in ≈43% of 35 Families With Midaortic Syndrome

Midaortic syndrome (MAS) is a rare cause of severe childhood hypertension characterized by narrowing of the abdominal aorta in children and is associated with extensive vascular disease. It may occur as part of a genetic syndrome, such as neurofibromatosis, or as consequence of a pathological inflammatory disease. However, most cases are considered idiopathic. We hypothesized that in a high percentage of these patients, a monogenic cause of disease may be detected by evaluating whole exome sequencing data for mutations in 1 of 38 candidate genes previously described to cause vasculopathy. We studied a cohort of 36 individuals from 35 different families with MAS by exome sequencing. In 15 of 35 families (42.9%), we detected likely causal dominant mutations. In 15 of 35 (42.9%) families with MAS, whole exome sequencing revealed a mutation in one of the genes previously associated with vascular disease (NF1, JAG1, ELN, GATA6, and RNF213). Ten of the 15 mutations have not previously been reported. This is the first report of ELN, RNF213, or GATA6 mutations in individuals with MAS. Mutations were detected in NF1 (6/15 families), JAG1 (4/15 families), ELN (3/15 families), and one family each for GATA6 and RNF213 Eight individuals had syndromic disease and 7 individuals had isolated MAS. Whole exome sequencing can provide conclusive molecular genetic diagnosis in a high fraction of individuals with syndromic or isolated MAS. Establishing an etiologic diagnosis may reveal genotype/phenotype correlations for MAS in the future and should, therefore, be performed routinely in MAS.

Whole Exome Sequencing of Patients with Steroid-Resistant Nephrotic Syndrome

BACKGROUND AND OBJECTIVES

Steroid-resistant nephrotic syndrome overwhelmingly progresses to ESRD. More than 30 monogenic genes have been identified to cause steroid-resistant nephrotic syndrome. We previously detected causative mutations using targeted panel sequencing in 30% of patients with steroid-resistant nephrotic syndrome. Panel sequencing has a number of limitations when compared with whole exome sequencing. We employed whole exome sequencing to detect monogenic causes of steroid-resistant nephrotic syndrome in an international cohort of 300 families.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Three hundred thirty-five individuals with steroid-resistant nephrotic syndrome from 300 families were recruited from April of 1998 to June of 2016. Age of onset was restricted to <25 years of age. Exome data were evaluated for 33 known monogenic steroid-resistant nephrotic syndrome genes.

RESULTS

In 74 of 300 families (25%), we identified a causative mutation in one of 20 genes known to cause steroid-resistant nephrotic syndrome. In 11 families (3.7%), we detected a mutation in a gene that causes a phenocopy of steroid-resistant nephrotic syndrome. This is consistent with our previously published identification of mutations using a panel approach. We detected a causative mutation in a known steroid-resistant nephrotic syndrome gene in 38% of consanguineous families and in 13% of nonconsanguineous families, and 48% of children with congenital nephrotic syndrome. A total of 68 different mutations were detected in 20 of 33 steroid-resistant nephrotic syndrome genes. Fifteen of these mutations were novel. NPHS1, PLCE1, NPHS2, and SMARCAL1 were the most common genes in which we detected a mutation. In another 28% of families, we detected mutations in one or more candidate genes for steroid-resistant nephrotic syndrome.

CONCLUSIONS

Whole exome sequencing is a sensitive approach toward diagnosis of monogenic causes of steroid-resistant nephrotic syndrome. A molecular genetic diagnosis of steroid-resistant nephrotic syndrome may have important consequences for the management of treatment and kidney transplantation in steroid-resistant nephrotic syndrome.

Whole exome sequencing frequently detects a monogenic cause in early onset nephrolithiasis and nephrocalcinosis

The incidence of nephrolithiasis continues to rise. Previously, we showed that a monogenic cause could be detected in 11.4% of individuals with adult-onset nephrolithiasis or nephrocalcinosis and in 16.7-20.8% of individuals with onset before 18 years of age, using gene panel sequencing of 30 genes known to cause nephrolithiasis/nephrocalcinosis. To overcome the limitations of panel sequencing, we utilized whole exome sequencing in 51 families, who presented before age 25 years with at least one renal stone or with a renal ultrasound finding of nephrocalcinosis to identify the underlying molecular genetic cause of disease. In 15 of 51 families, we detected a monogenic causative mutation by whole exome sequencing. A mutation in seven recessive genes (AGXT, ATP6V1B1, CLDN16, CLDN19, GRHPR, SLC3A1, SLC12A1), in one dominant gene (SLC9A3R1), and in one gene (SLC34A1) with both recessive and dominant inheritance was detected. Seven of the 19 different mutations were not previously described as disease-causing. In one family, a causative mutation in one of 117 genes that may represent phenocopies of nephrolithiasis-causing genes was detected. In nine of 15 families, the genetic diagnosis may have specific implications for stone management and prevention. Several factors that correlated with the higher detection rate in our cohort were younger age at onset of nephrolithiasis/nephrocalcinosis, presence of multiple affected members in a family, and presence of consanguinity. Thus, we established whole exome sequencing as an efficient approach toward a molecular genetic diagnosis in individuals with nephrolithiasis/nephrocalcinosis who manifest before age 25 years.

Mutations in KEOPS-complex genes cause nephrotic syndrome with primary microcephaly

Galloway-Mowat syndrome (GAMOS) is an autosomal-recessive disease characterized by the combination of early-onset nephrotic syndrome (SRNS) and microcephaly with brain anomalies. Here we identified recessive mutations in OSGEP, TP53RK, TPRKB, and LAGE3, genes encoding the four subunits of the KEOPS complex, in 37 individuals from 32 families with GAMOS. CRISPR-Cas9 knockout in zebrafish and mice recapitulated the human phenotype of primary microcephaly and resulted in early lethality. Knockdown of OSGEP, TP53RK, or TPRKB inhibited cell proliferation, which human mutations did not rescue. Furthermore, knockdown of these genes impaired protein translation, caused endoplasmic reticulum stress, activated DNA-damage-response signaling, and ultimately induced apoptosis. Knockdown of OSGEP or TP53RK induced defects in the actin cytoskeleton and decreased the migration rate of human podocytes, an established intermediate phenotype of SRNS. We thus identified four new monogenic causes of GAMOS, describe a link between KEOPS function and human disease, and delineate potential pathogenic mechanisms.

Indoor mold levels and current asthma among school-aged children in Saskatchewan, Canada

Current knowledge regarding the association between indoor mold exposures and asthma is still limited. The objective of this case-control study was to investigate the relationship between objectively measured indoor mold levels and current asthma among school-aged children. Parents completed a questionnaire survey of health history and home environmental conditions. Asthma cases had a history of doctor-diagnosed asthma or current wheeze without a cold in the past 12 months. Controls were age- and sex-matched to cases. Vacuumed dust samples were collected from the child's indoor play area and mattress. Samples were assessed for mold levels and quantified in colony-forming units (CFU). Sensitization to mold allergens was also determined by skin testing. Being a case was associated with family history of asthma, pet ownership, and mold allergy. Mold levels (CFU/m² ) in the dust samples of children's mattress and play area floors were moderately correlated (r = 0.56; P < 0.05). High mold levels (≥30 000 CFU/m² ) in dust samples from play [adjusted odds ratio (aOR) = 2.6; 95% CI: 1.03-6.43] and mattress (aOR) = 3.0; 95% CI: 1.11-8.00) areas were significantly associated with current asthma. In this study high levels of mold are a risk factor for asthma in children.

Whole exome sequencing identifies causative mutations in the majority of consanguineous or familial cases with childhood-onset increased renal echogenicity

Chronically increased echogenicity on renal ultrasound is a sensitive early finding of chronic kidney disease that can be detected before manifestation of other symptoms. Increased echogenicity, however, is not specific for a certain etiology of chronic kidney disease. Here, we performed whole exome sequencing in 79 consanguineous or familial cases of suspected nephronophthisis in order to determine the underlying molecular disease cause. In 50 cases, there was a causative mutation in a known monogenic disease gene. In 32 of these cases whole exome sequencing confirmed the diagnosis of a nephronophthisis-related ciliopathy. In 8 cases it revealed the diagnosis of a renal tubulopathy. The remaining 10 cases were identified as Alport syndrome (4), autosomal-recessive polycystic kidney disease (2), congenital anomalies of the kidney and urinary tract (3), and APECED syndrome (1). In 5 families, in whom mutations in known monogenic genes were excluded, we applied homozygosity mapping for variant filtering, and identified 5 novel candidate genes (RBM48, FAM186B, PIAS1, INCENP, and RCOR1) for renal ciliopathies. Thus, whole exome sequencing allows the detection of the causative mutation in 2/3 of affected individuals, thereby presenting the etiologic diagnosis and allows identification of novel candidate genes.

[Guideline on 'The treatment of recurrent varicose veins'Supplement to the Dutch Guideline on Venous disease]

The Dutch Guideline on Venous disease was lacking a section on recurrent varicose veins. The newly issued supplement on recurrent varicose veins fills this gap and provides clinicians with solutions concerning the management of patients with recurrent varicose veins following earlier treatment. Because venous disease is nowadays considered to be an ongoing disease, patients with this disorder will often require life-long care and different treatment than patients who have never been treated before.

Mutations in SLC26A1 Cause Nephrolithiasis

Nephrolithiasis, a condition in which urinary supersaturation leads to stone formation in the urinary system, affects about 5%-10% of individuals worldwide at some point in their lifetime and results in significant medical costs and morbidity. To date, mutations in more than 30 genes have been described as being associated with nephrolithiasis, and these mutations explain about 15% of kidney stone cases, suggesting that additional nephrolithiasis-associated genes remain to be discovered. To identify additional genes whose mutations are linked to nephrolithiasis, we performed targeted next-generation sequencing of 18 hypothesized candidate genes in 348 unrelated individuals with kidney stones. We detected biallelic mutations in SLC26A1 (solute carrier family 26 member 1) in two unrelated individuals with calcium oxalate kidney stones. We show by immunofluorescence, immunoblotting, and glycosylation analysis that the variant protein mimicking p.Thr185Met has defects in protein folding or trafficking. In addition, by measuring anion exchange activity of SLC26A1, we demonstrate that all the identified mutations in SLC26A1 result in decreased transporter activity. Our data identify SLC26A1 mutations as causing a recessive Mendelian form of nephrolithiasis.

Large-scale targeted sequencing comparison highlights extreme genetic heterogeneity in nephronophthisis-related ciliopathies

BACKGROUND

The term nephronophthisis-related ciliopathies (NPHP-RC) describes a group of rare autosomal-recessive cystic kidney diseases, characterised by broad genetic and clinical heterogeneity. NPHP-RC is frequently associated with extrarenal manifestations and accounts for the majority of genetically caused chronic kidney disease (CKD) during childhood and adolescence. Generation of a molecular diagnosis has been impaired by this broad genetic heterogeneity. However, recently developed high-throughput exon sequencing techniques represent powerful and efficient tools to screen large cohorts for dozens of causative genes.

METHODS

Therefore, we performed massively multiplexed targeted sequencing using the modified molecular inversion probe strategy (MIPs) in an international cohort of 384 patients diagnosed with NPHP-RC.

RESULTS

As a result, we established the molecular diagnoses in 81/384 unrelated individuals (21.1%). We detected 127 likely disease-causing mutations in 18 of 34 evaluated NPHP-RC genes, 22 of which were novel. We further compared a subgroup of current findings to the results of a previous study in which we used an array-based microfluidic PCR technology in the same cohort. While 78 likely disease-causing mutations were previously detected by the array-based microfluidic PCR, the MIPs approach identified 94 likely pathogenic mutations. Compared with the previous approach, MIPs redetected 66 out of 78 variants and 28 previously unidentified variants, for a total of 94 variants.

CONCLUSIONS

In summary, we demonstrate that the modified MIPs technology is a useful approach to screen large cohorts for a multitude of established NPHP genes in order to identify the underlying molecular cause. Combined application of two independent library preparation and sequencing techniques, however, may still be indicated for Mendelian diseases with extensive genetic heterogeneity in order to further increase diagnostic sensitivity.

IFT81, encoding an IFT-B core protein, as a very rare cause of a ciliopathy phenotype

Background

Bidirectional intraflagellar transport (IFT) consists of two major protein complexes, IFT-A and IFT-B. In contrast to the IFT-B complex, all components of IFT-A have recently been linked to human ciliopathies when defective. We therefore hypothesised that mutations in additional IFT-B encoding genes can be found in patients with multisystemic ciliopathies.

Methods

We screened 1628 individuals with reno-ocular ciliopathies by targeted next-generation sequencing of ciliary candidate genes, including all IFT-B encoding genes.

Results

Consequently, we identified a homozygous mutation in IFT81 affecting an obligatory donor splice site in an individual with nephronophthisis and polydactyly. Further, we detected a loss-of-stop mutation with extension of the deduced protein by 10 amino acids in an individual with neuronal ceroid lipofuscinosis-1. This proband presented with retinal dystrophy and brain lesions including cerebellar atrophy, a phenotype to which the IFT81 variant might contribute. Cultured fibroblasts of this latter affected individual showed a significant decrease in ciliated cell abundance compared with controls and increased expression of the transcription factor GLI2 suggesting deranged sonic hedgehog signalling.

Conclusions

This work describes identification of mutations of IFT81 in individuals with symptoms consistent with the clinical spectrum of ciliopathies. It might represent the rare case of a core IFT-B complex protein found associated with human disease. Our data further suggest that defects in the IFT-B core are an exceedingly rare finding, probably due to its indispensable role for ciliary assembly in development.

Urban-rural differences in asthma prevalence among young adolescents: The role of behavioural and environmental factors

BACKGROUND

Asthma prevalence has been reported to be lower in rural areas compared to urban areas, although this has been inconsistent. This study aims to identify the influence of urban-rural residence on asthma prevalence in adolescents in the Republic of Macedonia and to investigate characteristics that may explain observed associations.

METHODS

Following International Study of Asthma and Allergies in Childhood protocol, a national sample of Macedonian urban and rural dwelling adolescents (12-16 years) was recruited in 2006. Self-completed questionnaires were used to collect data on wheeze and asthma as well as personal, environmental and dietary characteristics. Following descriptive and multiple logistic regression analyses, a mediation analysis approach was performed to help explain observed associations.

RESULTS

A lower prevalence of current wheeze and ever-diagnosed asthma was observed in rural compared to urban dwelling adolescents (4.9% vs. 7.2% and 1.2% vs. 1.9%, respectively). After adjustment for potential confounders, the associations, although still protective, were not statistically significant (wheeze: OR=0.74, 95%CI=0.46-1.21; asthma: OR=0.97, 95%CI=0.38-2.46). The associations between urban-rural status with current wheeze and asthma were mediated by region of the country (wheeze 9%; asthma 19%) and by diet (>5% change for both wheeze and asthma). Having a dog resulted in a strengthening of the association between urban-rural status and current wheeze by 11.9%.

CONCLUSIONS

The prevalence of asthma and wheeze was lower in rural dwelling Macedonian adolescents and the association was mediated by the region of the country with diet likely to be part of the reason for this mediating effect.

Transiently active Wnt/β-catenin signaling is not required but must be silenced for stem cell function during muscle regeneration

Adult muscle’s exceptional capacity for regeneration is mediated by muscle stem cells, termed satellite cells. As with many stem cells, Wnt/β-catenin signaling has been proposed to be critical in satellite cells during regeneration. Using new genetic reagents, we explicitly test in vivo whether Wnt/β-catenin signaling is necessary and sufficient within satellite cells and their derivatives for regeneration. We find that signaling is transiently active in transit-amplifying myoblasts, but is not required for regeneration or satellite cell self-renewal. Instead, downregulation of transiently activated β-catenin is important to limit the regenerative response, as continuous regeneration is deleterious. Wnt/β-catenin activation in adult satellite cells may simply be a vestige of their developmental lineage, in which β-catenin signaling is critical for fetal myogenesis. In the adult, surprisingly, we show that it is not activation but rather silencing of Wnt/β-catenin signaling that is important for muscle regeneration.

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Wnt/β-catenin signaling is transiently active in myoblasts during muscle regeneration

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β-catenin is not required in myogenic cells for muscle regeneration

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β-catenin signaling in myoblasts must be silenced to limit the regenerative response

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β-catenin requirement and sensitivity differs in fetal and adult muscle stem cells

Evolutionarily conserved morphogenetic movements at the vertebrate head-trunk interface coordinate the transport and assembly of hypopharyngeal structures

The vertebrate head–trunk interface (occipital region) has been heavily remodelled during evolution, and its development is still poorly understood. In extant jawed vertebrates, this region provides muscle precursors for the throat and tongue (hypopharyngeal/hypobranchial/hypoglossal muscle precursors, HMP) that take a stereotype path rostrally along the pharynx and are thought to reach their target sites via active migration. Yet, this projection pattern emerged in jawless vertebrates before the evolution of migratory muscle precursors. This suggests that a so far elusive, more basic transport mechanism must have existed and may still be traceable today.

Here we show for the first time that all occipital tissues participate in well-conserved cell movements. These cell movements are spearheaded by the occipital lateral mesoderm and ectoderm that split into two streams. The rostrally directed stream projects along the floor of the pharynx and reaches as far rostrally as the floor of the mandibular arch and outflow tract of the heart. Notably, this stream leads and engulfs the later emerging HMP, neural crest cells and hypoglossal nerve. When we (i) attempted to redirect hypobranchial/hypoglossal muscle precursors towards various attractants, (ii) placed non-migratory muscle precursors into the occipital environment or (iii) molecularly or (iv) genetically rendered muscle precursors non-migratory, they still followed the trajectory set by the occipital lateral mesoderm and ectoderm. Thus, we have discovered evolutionarily conserved morphogenetic movements, driven by the occipital lateral mesoderm and ectoderm, that ensure cell transport and organ assembly at the head–trunk interface.

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At the vertebrate head–trunk interface, all tissues engage in stereotype cell movements.

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A ventrally–rostrally directed stream of cells leads along the floor of the pharynx to the developing jaw and outflow tract of the heart.

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The cell movements are spearheaded by the lateral mesoderm and surface ectoderm; muscle precursors for throat and tongue muscles (hypopharyngeal muscles); neural crest cells and outgrowing axons of the hypoglossal nerve follow.

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Hypopharyngeal muscle precursors follow the trajectory set by the lateral mesoderm and ectoderm, even when challenged with ectopic attractants or when rendered non-migratory.

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The newly discovered cell movements are the likely ground state for cell transport and organ assembly at the head–trunk interface before actively migrating muscle precursors evolved in “bony” (osteichthyan) vertebrates.

Tumescent, how do I do it?

Local perivenous anaesthesia has evolved from tumescent anaesthesia which has had a huge impact on liposuction procedures. Perivenous anaesthesia has had a similar effect on peripheral venous surgery. Safety during its application is further enhanced when combined with skilled ultrasound guidance and astute operator awareness.

Effect of assay specificity on the association of urine 11-dehydro thromboxane B2 determination with cardiovascular risk

BACKGROUND

Elevated urine 11-dehydro TXB(2), an indicator of persistent thromboxane generation in aspirin-treated patients, correlates with adverse cardiovascular outcome and has recently been identified as an independent risk factor for vein graft thrombosis after cardiac bypass surgery in the Reduction in Graft Occlusion Rates (RIGOR) study. The polyclonal antibody-based ELISA used to measure 11-dehydro TXB(2) in these previous studies is no longer clinically available and has been supplanted by a Food and Drug Administration (FDA)-cleared second-generation monoclonal antibody-based ELISA.

OBJECTIVES

To compare the laboratory and clinical performance of the first- and second-generation assays in a well-defined study population.

METHODS

11-dehydro TXB(2) was quantified in 451 urine samples from 229 Reduction in Graft Occlusion Rates (RIGOR) subjects using both ELISA. Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and spiking studies were used to investigate discordant assay results. The association of 11-dehydro TXB(2) to clinical outcome was assessed for each assay using multivariate modeling.

RESULTS

Median 11-dehydro TXB(2) levels were higher by monoclonal antibody- compared with polyclonal antibody-based ELISA (856 vs. 399 pg mg(-1) creatinine, P < 0.000001), with the latter providing values similar to UPLC-MS/MS. This discrepancy was predominantly as a result of cross-reactivity of the monoclonal antibody with 11-dehydro-2,3-dinor TXB(2), a thromboxane metabolite present in a similar concentration but with a poor direct correlation with 11-dehydro TXB(2). In contrast to the first-generation ELISA, 11-dehydro TXB(2) measured by the monoclonal antibody-based ELISA failed to associate with the risk of vein graft occlusion.

CONCLUSION

Quantification of urine 11-dehydro TXB(2) by monoclonal antibody-based ELISA was confounded by interference from 11-dehydro-2,3-dinor TXB(2) which reduced the accuracy and clinical utility of this second-generation assay.

Detection of varicose vein recurrence by duplex ultrasound: intra- and interobserver reproducibility

In a long-term follow-up study comparing saphenofemoral ligation and stripping with endovenous laser ablation, the groin is examined yearly by duplex ultrasound (DUS) to detect postoperative varicose vein recurrence. Clear criteria are needed for the uniformity of DUS observations. Physicians taking care of the follow-up were evaluated by an intra- and interobserver analysis. DUS films of 22 patients with no recurrence and 22 patients with recurrence of varicose veins were twice interpreted in two sessions. Observations were analysed by a kappa test. Interpretations of DUS by experienced observers show a kappa >7. Improved kappa results were measured over time in our physician in training. In conclusion, the reproducibility of DUS studies performed by the experienced observers of the study is excellent.

Comparative impact on prostanoid biosynthesis of celecoxib and the novel nonsteroidal anti-inflammatory drug CG100649

Nonsteroidal anti-inflammatory drugs (NSAIDs) elevate cardiovascular risk by disrupting cyclooxygenase-2 (COX-2)-dependent biosynthesis of prostacyclin (PGI(2)). CG100649 is a novel NSAID proposed to inhibit both COX-2 and carbonic anhydrase (CA)-I/-II. We compared its impact on prostanoid biosynthesis with that of celecoxib, an NSAID purposefully designed to selectively inhibit COX-2. In a controlled, double-blind randomized trial, single oral doses of 2 or 8 mg CG100649, 200 mg celecoxib, or placebo were well tolerated by healthy volunteers (n = 23). Both CG100649 and celecoxib had the effect of depressing urinary excretion of 2,3-dinor-6-keto-PGF(1α) (PGI-M); the effect of CG100649 was dose-dependent and more sustained (up to 240 h after the dose) than that of celecoxib. Neither CG100649 nor celecoxib significantly inhibited COX-1-dependent prostanoid formation. CA inhibition was not detected after administration of CG100649, despite its partitioning asymmetrically into erythrocytes. CG100649 and celecoxib are both relatively selective inhibitors of COX-2, but they differ in duration of action. Whether they have similar impact on cardiovascular events remains to be determined.

Satellite cells, connective tissue fibroblasts and their interactions are crucial for muscle regeneration

Muscle regeneration requires the coordinated interaction of multiple cell types. Satellite cells have been implicated as the primary stem cell responsible for regenerating muscle, yet the necessity of these cells for regeneration has not been tested. Connective tissue fibroblasts also are likely to play a role in regeneration, as connective tissue fibrosis is a hallmark of regenerating muscle. However, the lack of molecular markers for these fibroblasts has precluded an investigation of their role. Using Tcf4, a newly identified fibroblast marker, and Pax7, a satellite cell marker, we found that after injury satellite cells and fibroblasts rapidly proliferate in close proximity to one another. To test the role of satellite cells and fibroblasts in muscle regeneration in vivo, we created Pax7(CreERT2) and Tcf4(CreERT2) mice and crossed these to R26R(DTA) mice to genetically ablate satellite cells and fibroblasts. Ablation of satellite cells resulted in a complete loss of regenerated muscle, as well as misregulation of fibroblasts and a dramatic increase in connective tissue. Ablation of fibroblasts altered the dynamics of satellite cells, leading to premature satellite cell differentiation, depletion of the early pool of satellite cells, and smaller regenerated myofibers. Thus, we provide direct, genetic evidence that satellite cells are required for muscle regeneration and also identify resident fibroblasts as a novel and vital component of the niche regulating satellite cell expansion during regeneration. Furthermore, we demonstrate that reciprocal interactions between fibroblasts and satellite cells contribute significantly to efficient, effective muscle regeneration.

Medical treatment after peripheral bypass surgery over the past decade

OBJECTIVE

The Dutch Bypass and Oral anticoagulants or Aspirin (BOA) Study demonstrated that in patients with peripheral arterial disease after bypass surgery oral anticoagulants were more effective in preventing venous graft occlusions than aspirin, while aspirin was more effective in non-venous grafts. We evaluated if this finding was implemented in the clinical practice of former BOA participants by reconstructing a 10-year overview of their applied various drug treatments including anti-hypertensive and lipid-lowering drugs.

METHODS

In 482 patients from six centers that contributed most patients anti-thrombotic, anti-hypertensive, and lipid-lowering drug use was recorded at baseline (n = 478), retrospectively up to two years after BOA (n = 388), and prospectively for patients still alive between 2005 and 2009 (n = 209).

RESULTS

At baseline, 54% of patients received anti-thrombotics which increased to 96% at follow-up. At baseline 15% of patients were treated with lipid-lowering drugs and 49% with anti-hypertensives. This increased over time to 65% and 76%, respectively.

CONCLUSION

After the BOA Study its recommendations were applied marginally. Despite improvements over time, current lipid-lowering and anti-hypertensive drug use remained suboptimal. Our trend analyses, however, should be interpreted with caution, because drug use and compliance in survivors might be better than average.

Connective tissue fibroblasts and Tcf4 regulate myogenesis

Muscle and its connective tissue are intimately linked in the embryo and in the adult, suggesting that interactions between these tissues are crucial for their development. However, the study of muscle connective tissue has been hindered by the lack of molecular markers and genetic reagents to label connective tissue fibroblasts. Here, we show that the transcription factor Tcf4 (transcription factor 7-like 2; Tcf7l2) is strongly expressed in connective tissue fibroblasts and that Tcf4(GFPCre) mice allow genetic manipulation of these fibroblasts. Using this new reagent, we find that connective tissue fibroblasts critically regulate two aspects of myogenesis: muscle fiber type development and maturation. Fibroblasts promote (via Tcf4-dependent signals) slow myogenesis by stimulating the expression of slow myosin heavy chain. Also, fibroblasts promote the switch from fetal to adult muscle by repressing (via Tcf4-dependent signals) the expression of developmental embryonic myosin and promoting (via a Tcf4-independent mechanism) the formation of large multinucleate myofibers. In addition, our analysis of Tcf4 function unexpectedly reveals a novel mechanism of intrinsic regulation of muscle fiber type development. Unlike other intrinsic regulators of fiber type, low levels of Tcf4 in myogenic cells promote both slow and fast myogenesis, thereby promoting overall maturation of muscle fiber type. Thus, we have identified novel extrinsic and intrinsic mechanisms regulating myogenesis. Most significantly, our data demonstrate for the first time that connective tissue is important not only for adult muscle structure and function, but is a vital component of the niche within which muscle progenitors reside and is a critical regulator of myogenesis.

Randomised controlled trial comparing sapheno-femoral ligation and stripping of the great saphenous vein with endovenous laser ablation (980 nm) using local tumescent anaesthesia: one year results

OBJECTIVES

Comparison of sapheno-femoral ligation and stripping (SFL/S) versus endovenous laser ablation (EVLA, 980-nm) in the treatment of great saphenous vein (GSV) insufficiency, using local tumescent anaesthesia.

DESIGN

Randomised, single centre trial.

MATERIALS AND METHODS

Patients with GSV incompetence and varicose veins were randomised to either SFL/S or EVLA. At days 1, 2, 3, 7, 10, and 14 post-treatment, patients completed questionnaires on pain and quality of life. Recurrent varicose veins were evaluated by Duplex ultrasound (DUS) performed at 1 and 6 weeks, and 6 and 12 months.

RESULTS

130 legs in 121 patients were treated by SFL/S (n=68) or EVLA (n=62). Significantly more post-treatment pain was noted after EVLA at days 7, 10 and 14 (p<0.01; p<0.01; p=0.01), more hindrance in mobility at days 7 (p<0.01) and 10 (p=0.01), and in self care (p=0.03) and daily activities (p=0.01) at day 7 compared to SFL/S. DUS at 1-year follow-up showed 9% recurrences (5/56) after EVLA and 10% (5/49) after SFL/S.

CONCLUSION

Both SFL/S and EVLA, using local tumescent anaesthesia, were well tolerated, with no difference in short-term recurrence rate. In the second week after EVLA, patients experienced significantly more pain resulting in restricted mobility, self care and daily activity compared to SFL/S.

Effects of celecoxib on major prostaglandins in asthma

BACKGROUND

Prostaglandin (PG) D(2) is a pro-inflammatory and bronchoconstrictive mediator released from mast cells, and is currently evaluated as a new target for treatment of asthma and rhinitis. It is not known which cyclooxygenase (COX) isoenzyme catalyses its biosynthesis in subjects with asthma.

OBJECTIVES

Primarily, to assess whether treatment with the COX-2 selective inhibitor celecoxib inhibited biosynthesis of PGD(2) , monitored as urinary excretion of its major tetranor metabolite (PGDM). Secondarily, to determine the effects of the treatment on biosynthesis of PGE(2) , thromboxane A(2) and PGI(2) , also measured as major urinary metabolites.

METHODS

Eighteen subjects with asthma participated in a cross-over study where celecoxib 200mg or placebo were given b.i.d. on 3 consecutive days following 2 untreated baseline days. Six healthy controls received active treatment with the same protocol. Urinary excretion of the eicosanoid metabolites was determined by liquid chromatography/tandem mass spectrometry (LC/MS/MS). Lung function was followed as FEV(1) and airway inflammation as fraction of exhaled nitric oxide (F(E) NO).

RESULTS

Celecoxib treatment inhibited urinary excretion of PGEM by 50% or more in subjects with asthma and healthy controls, whereas there was no significant change in the excretion of PGDM. In comparison with the healthy controls, the subjects with asthma had higher baseline levels of urinary PGDM but not of PGEM. The 3-day treatment did not cause significant changes in FEV(1) or F(E) NO.

CONCLUSION AND CLINICAL RELEVANCE

Biosynthesis of PGD(2) was increased in subjects with asthma and its formation is catalysed predominantly by COX-1. By contrast, COX-2 contributes substantially to the biosynthesis of PGE(2) . The asymmetric impact of celecoxib on prostanoid formation raises the possibility of long-term adverse consequences of COX-2 inhibition on airway homeostasis by the decreased formation of bronchodilator PGs and maintained production of increased levels of bronchoconstrictor PGs in asthmatics.

Aspirin reduces the prothrombotic activity of C-reactive protein

AIM

C-reactive protein (CRP) is a risk marker and a potential modulator of vascular disease. Previous studies support a prothrombotic activity of CRP, with impaired thromboregulation. The present study examined the antithrombotic effect of aspirin in mice transgenic for human CRP (CRPtg mice). Mechanistic investigations further elucidated the effect of CRP on prostanoid metabolism in vivo and in vitro.

METHODS AND RESULTS

Administration of aspirin (30 mg kg(-1) day(-1)) to CRPtg mice slowed the accelerated thrombosis after photochemical injury to the carotid (99 +/- 32 vs. 45 +/- 24 min and 75 +/- 23 vs. 82 +/- 26 min in wild-type mice vs. CRPtg mice, without and following aspirin treatment, respectively). Vascular injury modulated the expression of key pathways in prostanoid metabolism differently in CRPtg mice and wild-type mice. Suppression of cyclo-oxygenase 2 (COX-2)-derived metabolism with suppression of prostaglandin I2 (PGI2) synthase and PGI2 metabolism was recorded in the injured artery with increased thromboxane receptor expression. Aspirin therapy reduced the difference in PGI2 biosynthesis between CRPtg mice and wild-type mice. In vitro studies in human-derived cells further supported these findings. Incubation of human umbilical vein endothelial cells (HUVECs) with human recombinant CRP (5 microg mL(-1)) suppressed PGI2 synthase expression and significantly increased thromboxane receptor levels. Incubation of smooth muscle cells with CRP did not affect prostanoid expression.

CONCLUSIONS

CRP modulates prostanoid metabolism to favor vascular occlusion. Elevated CRP levels might predispose to the cardiovascular hazard conferred by selective COX-2 inhibitors, and the risk mediated by CRP may be limited by aspirin.

Assessment of endotoxin levels in the home and current asthma and wheeze in school-age children

The relationship between household endotoxin and asthma in children is not clear. To further investigate the relationship between sources of endotoxin and childhood asthma, we conducted a case-control study of children with and without asthma and examined their more frequent household exposures in the home. Children ages 6-13 years with current asthma (n = 70) or wheeze only (n = 19) were sex and age matched (+/-1 year) to 107 controls. Play area and mattress dust were collected for endotoxin analysis. Atopic status was determined by skin prick testing for allergies. A family size of >4 per household was associated with higher endotoxin levels (EU/mg) in the bed dust (P < 0.05). Passive smoking (P < 0.05) and the presence of a cat were associated with higher levels of endotoxin in mattress dust. Endotoxin levels in either the play dust or the bed dust did not differ between cases and controls. Within atopic cases, those with higher endotoxin loads (EU/m2) in bed or play areas were more likely to miss school for chest illness (P < 0.05). In this study, household endotoxin is not a risk factor for current asthma overall but may be associated with increased severity in children with atopic asthma.

PRACTICAL IMPLICATIONS

This study did not find that household sources of endotoxin were associated with asthma. However, within atopic asthmatics, asthma severity (as measured by a history of being kept home from school because of a chest illness in the past year) was associated with higher levels of endotoxin in dust from the child's bed. There is a need to further investigate the nature of the relationship between household endotoxin and asthma severity in children which could lead to better management of childhood asthma.

Respiratory response to endotoxin and dust predicts evidence of inflammatory response in volunteers in a swine barn

BACKGROUND

It has been shown that exposure in intense exposure in swine barn facilities is associated with increased respiratory symptoms and reduction in pulmonary functions. This study investigated if systemic response could be predicted by FEV(1) response following swine barn exposure.

METHODS

Naïve males were tested at baseline, low and high endotoxin and dust levels. Subjects were classified as "more responsive" (n = 9) or "less responsive" (n = 11) based on FEV(1) reduction following high endotoxin exposure. Health measures included pulmonary function testing, blood samples and nasal lavage. Environmental samples were collected from the barn.

RESULTS

White blood cells and blood lymphocytes at low exposure were significantly greater in those who were "more responsive" compared to those who were "less responsive". There was a significant increase in blood lymphocytes, serum IL6, total nasal lavage cells and nasal IL8 at high exposure among "more responsive" subjects compared to "less responsive" subjects.

CONCLUSIONS

Respiratory response to high-level endotoxin and dust exposure predicts evidence of inflammatory response throughout a range of endotoxin and dust exposures.

The impact of epilepsy surgery on quality of life in children

OBJECTIVE

To determine if epilepsy surgery is effective in improving the quality of life (QOL) of children with intractable seizures using the Quality of Life in Childhood Epilepsy Questionnaire (QOLCE).

METHODS

The authors conducted a prospective study of the families of 35 children with intractable epilepsy who underwent epilepsy surgery. Parents completed the QOLCE preoperatively and again 6 to 18 months after surgery. At both assessment dates parents indicated the severity of their child's seizures during the past 6 months and the frequency of their child's seizures during the past 4 weeks on Likert-type scales. Children were split into two groups according to surgery outcome: seizure free vs persistent seizures. Statistical analyses were conducted to determine if children rendered seizure free showed a greater improvement in QOL compared to those with persistent seizures postoperatively.

RESULTS

Greater improvement in QOL was documented for children rendered seizure free vs children with persistent seizures. This was significant for the overall QOLCE QOL score and subscales assessing cognitive, social, emotional, behavioral, and physical domains of life.

CONCLUSIONS

Epilepsy surgery improves the quality of life of children rendered seizure free. Families can be counseled preoperatively of the potential benefits of surgery beyond seizure reduction.

Outcome After Occlusion of Infrainguinal Bypasses in the Dutch BOA Study: Comparison of Amputation Rate in Venous and Prosthetic Grafts

OBJECTIVE

To compare the consequences of occlusion of infrainguinal venous and prosthetic grafts.

METHODS

In total, 2690 patients were included in the Dutch BOA study, a multicenter randomised trial that compared the effectiveness of oral anticoagulants with aspirin in the prevention of infrainguinal bypass graft occlusion. Two thousand four hundred and four patients received a femoropopliteal or femorodistal bypass with a venous (64%) or prosthetic (36%) graft. The incidence of occlusion and amputation was calculated according to graft material and the incidence of amputation after occlusion was compared with Cox regression to adjust for differences in prognostic factors.

RESULTS

The indication for operation was claudication in 51%, rest pain in 20% and tissue loss in 28% of patients. The mean follow up was 21 months. After venous bypass grafting 171 (15%) femoropopliteal and 96 (24%) femorodistal grafts occluded. After prosthetic bypass grafting 234 (30%) femoropopliteal and 25 (38%) femorodistal grafts occluded. Patients with occlusions in the venous group had more severe ischemia, less runoff vessels and were older than the patients with prosthetic grafts. In the venous occlusion group 54 (20%) amputations were performed compared to 42 (16%) in the prosthetic occlusion group; crude hazard ratio 1.17 (95% CI 0.78-1.75). After adjustment for above mentioned differences in patient characteristics the hazard ratio was 0.86 (95% CI 0.56-1.32).

CONCLUSION

The need for amputation after occlusion is not influenced by graft material in infrainguinal bypass surgery.

Risk of Major Haemorrhage in Patients after Infrainguinal Venous Bypass Surgery: Therapeutic Consequences? The Dutch BOA (Bypass Oral Anticoagulants or Aspirin) Study

OBJECTIVES

The beneficial effect of oral anticoagulants after infrainguinal venous bypass surgery is compromised by bleeding complications. We developed a model to identify patients, treated with anticoagulation, at risk of major haemorrhage and estimated whether this complication could have been prevented if patients had received aspirin.

DESIGN

Randomised clinical trial.

METHODS

Data of patients who participated in the Dutch Bypass Oral Anticoagulation or Aspirin Study were reanalysed using Cox regression. After infrainguinal bypass surgery these patients were randomised to oral anticoagulants (n = 1326) or aspirin (n = 1324).

RESULTS

Predictors of major haemorrhage for patients on oral anticoagulants were increased systolic blood pressure (> or = 140 mmHg, hazard ratio [HR] 1.62), age > or = 75 years (HR 2.77) and diabetes mellitus (HR 1.60). If the 345 patients in the highest risk quartile had received aspirin, major haemorrhages would have been reduced from 46 to 22, with no major changes in ischemic events and graft occlusions. In the subgroup with venous bypasses major haemorrhages would have been reduced from 27 to 13, at the cost of seven more ischemic events (mostly fatal) and 17 more graft occlusions.

CONCLUSIONS

Treating patients at highest risk of major haemorrhage with aspirin instead of oral anticoagulants would have resulted in a reduction of non-fatal haemorrhages, but for venous bypasses this reduction was outweighed by an increase in ischemic events and graft occlusions. We still recommend treatment with oral anticoagulants after peripheral venous bypass surgery.

Occupational asthma in newly employed workers in intensive swine confinement facilities

Respiratory symptoms, reductions in pulmonary function and increased bronchial responsiveness have been described in exposed workers and in naïve volunteers exposed to intensive swine production facilities. Typically, this occurs in persons who have been employed for a long duration or in previously unexposed, naïve volunteers. The current authors describe four cases, all female, who developed acute onset of wheezing and cough suggestive of asthma within weeks of commencing full-time employment in intensive swine production facilities. None of the workers were aware of any previous asthma, allergies or hay fever. All four employees reported improvement of symptoms on cessation of work in the facilities and consequent withdrawal from exposure. However, when seen at the respiratory clinic, cases 1 and 3 continued to be either mildly symptomatic or were taking medications with continued borderline airways responsiveness, as measured by methacholine challenge test up to 4 and 5 months, respectively, following work cessation. Case 2 continued to have symptoms for > or =3 months after work cessation. Only case 1, however, was seen at repeated visits in the respiratory clinic. One worker participated in a work re-entry trial and experienced profound coughing and chest tightness within an hour of entry, after which, the trial had to be terminated. Provocative concentration causing a 20% fall in forced expiratory volume in one second (PC20) measured 5 h later was lower than pre-trial PC20. No acute exposure event was recorded in the workers prior to the onset of symptoms. To the current authors' knowledge, this is the first report of occupational asthma occurring in newly employed full-time intensive swine production workers after a short-term exposure and should raise awareness that previously unexposed workers may be at risk of developing what would appear to be long-term asthma after relatively short-term exposure.

Biomarkers of oxidative stress study III. Effects of the nonsteroidal anti-inflammatory agents indomethacin and meclofenamic acid on measurements of oxidative products of lipids in CCl4 poisoning

Plasma and urinary levels of malondialdehyde-like products (MDA) and isoprostanes were identified as markers of in vivo lipid peroxidation in an animal model of CCl4 poisoning. We sought to determine the extent to which the formation of these oxidation products is influenced by inhibition of the cyclooxygenase enzymes which catalytically generate proinflammatory lipid peroxidation products known as prostaglandins and thromboxane. In the present studies, after induction of oxidant stress in rats with CCl4, lipid peroxidation products measured in plasma and urine demonstrate that isoprostanes and MDA can be partially inhibited by cyclooxygenase inhibitors, albeit to different extents. The lowering of isoprostane and MDA formation, however, may not to due primarily to the diminution of catalytic generation of isoprostanes or MDA by the cyclooxygenases but, rather, may be the result of the suppression of nonenzymatic lipid peroxidation. This is suggested since 8,12-iso-iPF2alpha-VI is also reduced by indomethacin, yet, unlike other isoprostanes and MDA, it is not generated catalytically by the cyclooxygenase. Thus, although the two cyclooxygenase inhibitors we tested have statistically significant effects on the measurements of both isoprostanes and MDA in this study, the results provide evidence that these lipid-degradation products primarily constitute markers of oxidative stress.

Biomarkers of oxidative stress study II: are oxidation products of lipids, proteins, and DNA markers of CCl4 poisoning?

Oxidation products of lipids, proteins, and DNA in the blood, plasma, and urine of rats were measured as part of a comprehensive, multilaboratory validation study searching for noninvasive biomarkers of oxidative stress. This article is the second report of the nationwide Biomarkers of Oxidative Stress Study using acute CCl4 poisoning as a rodent model for oxidative stress. The time-dependent (2, 7, and 16 h) and dose-dependent (120 and 1200 mg/kg i.p.) effects of CCl4 on concentrations of lipid hydroperoxides, TBARS, malondialdehyde (MDA), isoprostanes, protein carbonyls, methionine sulfoxidation, tyrosine products, 8-hydroxy-2'-deoxyguanosine (8-OHdG), leukocyte DNA-MDA adducts, and DNA-strand breaks were investigated to determine whether the oxidative effects of CCl4 would result in increased generation of these oxidation products. Plasma concentrations of MDA and isoprostanes (both measured by GC-MS) and urinary concentrations of isoprostanes (measured with an immunoassay or LC/MS/MS) were increased in both low-dose and high-dose CCl4-treated rats at more than one time point. The other urinary markers (MDA and 8-OHdG) showed significant elevations with treatment under three of the four conditions tested. It is concluded that measurements of MDA and isoprostanes in plasma and urine as well as 8-OHdG in urine are potential candidates for general biomarkers of oxidative stress. All other products were not changed by CCl4 or showed fewer significant effects.

Distinct clinicopathologic subtypes of cortical dysplasia of Taylor

BACKGROUND

Two pathologic subtypes based on the presence or absence of balloon cells have been described in cortical dysplasia of Taylor (CDT).

OBJECTIVE

To determine whether the pathologic subtype has any distinct clinical or MRI features that are relevant to management.

METHODS

The histopathologic, clinical, and MRI features of 34 children with CDT who underwent epilepsy surgery at Miami Children's Hospital from 1990 to 2001 were investigated.

RESULTS

Bizarre neuronal cytomegaly was the primary pathologic feature of 15 patients with the dysplasia-only subtype, and 19 cases showed additional characteristics including balloon cells and marked white matter abnormalities. Both groups presented with severe intractable epilepsy of very-early-onset, multiple daily seizures, cognitive disability, and focal neurologic deficits. The dysplasia-only subtype had higher rates of neonatal onset, hemiparesis, and severe mental retardation (p < 0.05). The MRI features of focal cortical thickening with associated cortical T2 signal change showed excellent sensitivity (94%) and reasonable specificity (73%) for the diagnosis of the balloon cell subtype. The overall surgical outcome was 59% seizure freedom at 2 years.

CONCLUSIONS

Children with cortical dysplasia of Taylor type have in common a very-early-onset, severe epilepsy with neurologic co-morbidity. Patients with the non-balloon cell pathologic subtype have a more severe phenotype. A trend toward a better outcome in the balloon cell group suggests that preoperative identification of these subtypes may impact surgical planning.

Memory function in childhood epilepsy syndromes

OBJECTIVE

Children with epilepsy are at risk of specific cognitive deficits. We aimed to compare and characterize the memory function of children with childhood absence epilepsy (CAE), frontal lobe epilepsy (FLE) and temporal lobe epilepsy (TLE).

METHODS

Epilepsy syndrome was identified by clinical data, seizure semiology, interictal and ictal electroencephalogram (EEG). Seventy children aged 6-18 years with CAE, FLE or TLE had neuropsychological assessment including memory function. After adjusting for epilepsy variables, neuropsychological results of the syndrome groups and normative data were compared.

RESULTS

Children from all three syndrome groups were at risk of memory difficulties. The duration of epilepsy correlated negatively with memory function. Children with TLE had the worst memory function, significantly lower in verbal memory tasks than children with CAE (P = 0.02) and children with FLE (P = 0.01). The performance of children with TLE was significantly below the normed mean across all verbal and most visual tasks. Compared to the normed means, children with FLE had results that were statistically lower in some verbal and visual tasks, and children with CAE were lower in two visual tasks only.

CONCLUSIONS

This study demonstrates memory dysfunction in three common childhood epilepsy syndromes. Children with TLE had the greatest impairment, children with FLE had memory difficulties not previously reported, and children with CAE had subtle memory deficits. Qualitative differences were also evident. Longer duration of intractable epilepsy was associated with reduced memory ability. Memory function and its potential impact on academic achievement are vital considerations when managing children with epilepsy.

The health-related quality of life of childhood epilepsy syndromes

OBJECTIVE

There is increasing awareness of the importance of assessing physical, psychological, social and behavioural well-being in chronic disease. The aim of this study was to examine the health-related quality of life (HRQoL) of children with common epilepsy syndromes and to explore if there are HRQoL differences between those syndromes.

METHODS

Each child had their epilepsy syndrome defined according to the International League Against Epilepsy classification. Epilepsy syndromes included symptomatic frontal, temporal, parietal/occipital lobe and partial unlocalized epilepsy, and two idiopathic epilepsies, childhood absence epilepsy (CAE) and benign rolandic epilepsy (BRE). Seizure semiology and ictal/interictal electroencephalogram (EEG) were determined for symptomatic partial epilepsy syndromes by video-EEG monitoring. HRQoL was evaluated with an epilepsy-specific instrument, the Quality of Life in Childhood Epilepsy Questionnaire, and two generic instruments, the Child Health Questionnaire and Child Behavior Checklist.

RESULTS

Children with symptomatic partial epilepsy syndromes were affected by epilepsy in a similar way and did not have unique HRQoL profiles. However, these children had significantly lower HRQoL scores compared to those with CAE or BRE. All children with epilepsy regardless of syndrome had a higher frequency of behavioural problems compared to normative data.

CONCLUSION

These results indicate that children with epilepsy regardless of syndrome require evaluation of the psychosocial implications. There is a greater impact on HRQoL in symptomatic epilepsy compared to idiopathic epilepsy. Specific symptomatic partial syndromes did not differ in the degree they affect HRQoL. These findings have important implications for clinicians caring for children with epilepsy.

The influence of hyperhomocysteinemia on graft patency after infrainguinal bypass surgery in the Dutch BOA Study

OBJECTIVE

Hyperhomocysteinemia has been identified as a risk factor for (cardio)vascular disease. Whether hyperhomocysteinemia contributes to graft failure after peripheral bypass surgery remains unclear. The present study evaluated the influence of hyperhomocysteinemia on graft patency after infrainguinal bypass surgery.

DESIGN

The present study was designed as a nested case-control study.

METHOD

In this study (nested in the Dutch Bypass Oral anticoagulants or Aspirin Study), 150 patients with graft occlusion were each matched with two randomly selected controls with patent grafts (N = 299) from the same trial. Venous blood samples were drawn from cases and controls, and total plasma homocysteine (tHcy) was determined. Mean serum homocysteine levels and the presence of hyperhomocysteinemia (>95th percentile in healthy individuals) were compared between cases and controls.

RESULTS

No significant differences were found between serum levels of homocysteine in patients with and without graft occlusion. The mean plasma homocysteine levels were 14.4 micromol/L and 14.9 micromol/L in the case and control groups, respectively. The resulting mean difference was -0.4 (95% confidence interval [CI], -1.8-0.9). The odds ratio of hyperhomocysteinemia was 0.81 (95% CI, 0.49-1.33). Adjustment for risk factors of graft occlusion did not change these results.

CONCLUSIONS

Postoperative raised serum levels of homocysteine proved not to be a risk factor for graft occlusion after infrainguinal bypass grafting.

Clinical, EEG, and quantitative MRI differences in pediatric frontal and temporal lobe epilepsy

OBJECTIVE

To examine the clinical, electrographic, and quantitative MRI differences between frontal lobe (FLE) and mesial temporal lobe epilepsy (MTLE) in children.

METHODS

The population included children who underwent video-EEG monitoring between 1995 and 2000 who were classified as either FLE (n = 39) or MTLE (n = 17) according to the criteria of the International League Against Epilepsy. Clinical, EEG, and quantitative MRI data (including frontal cortical volumes) were compared between the two syndromes and a control group (n = 42).

RESULTS

In FLE, seizures were significantly briefer, more frequent, and predominantly from sleep, and had differing motor characteristics. The rates of bilateral epileptiform interictal and ictal EEG abnormalities were significantly higher in FLE. A nonlesional MRI was significantly more common in FLE. Mean frontal cortical volume in FLE was significantly lower than MTLE and controls. Seizure freedom after surgery was lower in FLE.

CONCLUSIONS

The clinical syndrome of FLE is clearly distinct from MTLE. The etiology of this disorder is unknown in the majority of cases despite extensive investigation. Because of a lack of a clearly defined etiology and frequent nonlateralizing EEG changes, few of these children are considered optimal surgical candidates. The demonstration of bilateral frontal cortical volume loss and bilateral EEG abnormalities suggests that FLE is a bilateral disease in a high proportion of patients. The outcome in those patients who were deemed surgical candidates was significantly worse than the MTLE cases.

Characterization of a novel hemoglobin-glutathione adduct that is elevated in diabetic patients

BACKGROUND

Typically, a diagnosis of diabetes mellitus is based on elevated circulating blood glucose levels. In an attempt to discover additional markers for the disease and predictors of prognosis, we undertook the characterization of HbA1d3 in diabetic and normal patients.

MATERIAL AND METHODS

PolyCAT A cation exchange chromatography and liquid chromatography-mass spectroscopy was utilized to separate the alpha- and beta-globin chains of HbA1d3 and characterize their presence in normal and diabetic patients.

RESULTS

We report the characterization of HbA1d3 as a glutathionylated, minor hemoglobin subfraction that occurs in higher levels in diabetic patients (2.26 +/- 0.29%) than in normal individuals (1.21 +/- 0.14%, p < 0.001). The alpha-chain spectrum displayed a molecular ion of m/z 15126 Da, which is consistent with the predicted native mass of the HbA0 alpha-globin chain. By contrast, the mass spectrum of the beta-chain showed a mass excess of 307 Da (m/z = 16173 Da) versus that of the native HbA0 beta-globin chain (m/z = 15866 Da). The native molecular weight of the modified beta-globin chain HbA0 was regenerated by treatment of HbA1d3 with dithiothreitol, consistent with a glutathionylated adduct.

CONCLUSIONS

We propose that HbA1d3 (HbSSG) forms normally in vivo, and may provide a useful marker of oxidative stress in diabetes mellitus and potentially other pathologic situations.