Progress Towards Using Linked Population-Based Data For Geohealth Research: Comparisons Of Aotearoa New Zealand And The United Kingdom

Globally, geospatial concepts are becoming increasingly important in epidemiological and public health research. Individual level linked population-based data afford researchers with opportunities to undertake complex analyses unrivalled by other sources. However, there are significant challenges associated with using such data for impactful geohealth research. Issues range from extracting, linking and anonymising data, to the translation of findings into policy whilst working to often conflicting agendas of government and academia. Innovative organisational partnerships are therefore central to effective data use. To extend and develop existing collaborations between the institutions, in June 2019, authors from the Leeds Institute for Data Analytics and the Alan Turing Institute, London, visited the Geohealth Laboratory based at the University of Canterbury, New Zealand. This paper provides an overview of insight shared during a two-day workshop considering aspects of linked population-based data for impactful geohealth research. Specifically, we discuss both the collaborative partnership between New Zealand's Ministry of Health (MoH) and the University of Canterbury's GeoHealth Lab and novel infrastructure, and commercial partnerships enabled through the Leeds Institute for Data Analytics and the Alan Turing Institute in the UK. We consider the New Zealand Integrated Data Infrastructure as a case study approach to population-based linked health data and compare similar approaches taken by the UK towards integrated data infrastructures, including the ESRC Big Data Network centres, the UK Biobank, and longitudinal cohorts. We reflect on and compare the geohealth landscapes in New Zealand and the UK to set out recommendations and considerations for this rapidly evolving discipline.

Surgical decision-making in infants with suspected UPJ obstruction: stakeholder perspectives

INTRODUCTION

Although there are significant demographic and clinical variations in treatment decisions for infants with high-grade hydronephrosis concerning for ureteropelvic junction obstruction (UPJO), there has been little research on the roles of parents and surgeons in the surgical decision-making (DM) process.

OBJECTIVE

The purpose of this study was to understand parents' and surgeons' perceived roles in the surgical DM process for infants with high-grade hydronephrosis.

STUDY DESIGN

Semistructured interviews were conducted with pediatric urologists from three regionally diverse tertiary referral sites and parents of infants diagnosed and treated for unilateral Society for Fetal Urology grade 3 or 4 hydronephrosis at one tertiary pediatric urology practice. Purposive sampling was used to ensure adequate representation of parents based on treatment choice, patient gender, race/ethnicity, and distance from the practice. Survey domains included (1) discussions about diagnosis and treatment options, (2) factors guiding treatment choice, and (3) participants' role in the DM process. Transcribed data and field notes were analyzed using a team-based, inductive grounded theory qualitative approach.

RESULTS

Thirteen physicians and 32 parents were interviewed between November 2016 and November 2017. Parents and surgeons agreed that the surgeon was best equipped to guide treatment decisions because of their clinical knowledge and experience. Parents reported that their trust in the surgeon was the primary factor in their decisions. Surgeons reported tailoring discussions with parents to not only educate them about treatment options but also to develop an ongoing relationship with parents. Both parents and surgeons reported being satisfied with their roles in the DM process.

DISCUSSION

This study suggests that parental trust in the surgeon and surgeon recommendations drive DM. This may be due to a lack of explicit discussion of options or of parental values and preferences for care. Limited discussions may also impact parental understanding of risks and potential complications. These findings are similar to those of prior studies in adults and children considering elective surgery.

CONCLUSIONS

In this study, parents and surgeons reported that surgeon recommendations, rather than parent preferences, guide treatment choices for infants with suspected UPJO. Both parents and surgeons are satisfied with a physician-driven approach to DM, suggesting that, in situations where the perceived risk is low and parental knowledge is limited, parents may find a physician-led approach beneficial. Data gleaned from this study will be used to inform future quantitative studies evaluating factors guiding surgeon recommendations for treatment and their associations with underlying treatment variation.

Role of the 12-lipoxygenase pathway in diabetes pathogenesis and complications

12-lipoxygenase (12-LOX) is one of several enzyme isoforms responsible for the metabolism of arachidonic acid and other poly-unsaturated fatty acids to both pro- and anti-inflammatory lipid mediators. Mounting evidence has shown that 12-LOX plays a critical role in the modulation of inflammation at multiple checkpoints during diabetes development. Due to this, interventions to limit pro-inflammatory 12-LOX metabolites either by isoform-specific 12-LOX inhibition, or by providing specific fatty acid substrates via dietary intervention, has the potential to significantly and positively impact health outcomes of patients living with both type 1 and type 2 diabetes. To date, the development of truly specific and efficacious inhibitors has been hampered by homology of LOX family members; however, improvements in high throughput screening have improved the inhibitor landscape. Here, we describe the function and role of human 12-LOX, and mouse 12-LOX and 12/15-LOX, in the development of diabetes and diabetes-related complications, and describe promise in the development of strategies to limit pro-inflammatory metabolites, primarily via new small molecule 12-LOX inhibitors.

Mechanical properties and biocompatibility of the sputtered Ti doped hydroxyapatite

The hydroxyapatite enriched with Ti were prepared as possible candidates for biomedical applications especially for implantable devices that are in direct contact to the bone. The hydroxyapatites with different Ti content were prepared by RF magnetron sputtering on Ti-6Al-4V alloy using pure hydroxyapatite and TiO2 targets. The content of Ti was modified by changing the RF power fed on TiO2 target. The XPS and FTIR analyses revealed the presence of hydroxyapatite structure. The hardness and elastic modulus of the hydroxyapatite were increased by Ti addition. After 5 days of culture, the cell viability of the Ti-6Al-4V was enhanced by depositing with undoped or doped hydroxyapatite. The Ti additions led to an increase in cell viability of hydroxyapatite, after 5 days of culture. The electron microscopy showed the presence of more cells on the surface of Ti-enriched hydroxyapatite than those observed on the surface of the uncoated alloys or undoped hydroxyapatite.

Polymeric Based Therapeutic Delivery Systems Prepared Using Electrohydrodynamic Processes

The development of therapeutic dosage (e.g. pharmaceutical) systems is an ongoing process which, in recent times has incorporated several emerging disciplines and themes at timely intervals. While the concepts surrounding dosage forms have developed and evolved, many polymeric excipients remain as the preferred choice of materials over existing counterparts, serving functions as matrix materials, coatings and providing other specific functional properties (e.g. adhesion, controlled release and mechanical properties). There have been, however, developments in the deployment of synthetic polymeric materials (e.g. polycaprolactone, poly lactic co-glycolic acid) when compared to naturally occurring materials (e.g. lactose, gelatin). Advances in pharmaceutical process technologies have also provided novel engineering platforms to develop a host of exciting structure based materials ranging from the nanometer to the macro scales. Some of these structure enabling technologies include spray drying, super critical processing, microfluidics and even wet chemical methods. More recently electrohydrodynamic (EHDA) engineering methods have emerged as robust technologies offering potential to fabricate a plethora of generic structures (e.g. particles, fibres, bubbles and pre-determined patterns) on a broad scale range. This review focuses on key developments using various EHDA technologies for the pharmaceutical and biomaterial remits when selecting synthetic and/or naturally occurring polymers as pharmaceutical (and therapeutic) excipients. In addition, the underlying EHDA process principles are discussed along with key parameters and variables (both materials and engineering). EHDA technologies are operational at ambient conditions and recent developments have also demonstrated their viability for large scale production. These are promising technologies which have potential in established (e.g. films, dressings and microparticles) and emerging scientific themes (e.g. nanomedicines and tissue engineering).

Interaction between cytokines and inflammatory cells in islet dysfunction, insulin resistance and vascular disease

Inflammation is an established pathogenic player in insulin resistance, islet demise and atherosclerosis. The complex interactions between cytokines, immune cells and affected tissues result in sustained inflammation in diabetes and atherosclerosis. 12- and 15-lipoxygenase (LO), such as 12/15-LO, produces a variety of metabolites through peroxidation of fatty acids and potentially contributes to the complex molecular crosstalk at the site of inflammation. 12- and 15-LO pathways are frequently activated in tissues affected by diabetes and atherosclerosis including adipose tissue (AT), islets and the vasculature. Moreover, mice with whole body and tissue-specific knockout of 12/15-LO are protected against insulin resistance, hyperglycaemia and atherosclerosis supporting functional contribution of 12- and 15-LO pathways in diabetes and atherosclerosis. Recently, it has emerged that there is a temporal regulation of the particular isoforms of 12- and 15-LO in human AT and islets during the development of type 1 and type 2 diabetes and obesity. Analyses of tissues affected by diabetes and atherosclerosis also implied the roles of interleukin (IL)-12 and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-1 (NOX-1) in islets and IL-17A in atherosclerosis. Future studies should aim to test the efficacy of inhibitions of these mediators for treatment of diabetes and atherosclerosis.

Effect of Rotation Relationship Between γ Grains on Compatibility of Deformation of Ti-A1 Alloys

The specific rotation relationships between adjacent γ grains have been measured in an alloy of composition Ti-47.5Al-2.5Cr consisting of lamellar and equiaxed distributions of γ grains in which the α2 phase was distributed as long lamellae or smaller globules respectively. Detailed analyses of active slip systems have been carried out by TEM observations of deformed samples and from these, the effect that specific rotations between γ grains have on the compatibility of deformation across adjacent grains has been discussed. Theoretical calculations of the geometric compatibility factor characterising the best slip transfer across adjacent grains have been used and compared to the experimental results. It has been possible to deduce the role played by the type of orientation relationship between grains in producing active deformation systems that allow the maximum compatibility of deformation.

Characterization of aluminium-based water treatment residual for potential phosphorus removal in engineered wetlands

Aluminium-based water treatment residual (Al-WTR) is the most widely generated residual from water treatment facilities worldwide. It is regarded as a by-product of no reuse potential and landfilled. This study assessed Al-WTR as potential phosphate-removing substrate in engineered wetlands. Results indicate specific surface area ranged from 28.0 m(2) g(-1) to 41.4 m(2) g(-1). X-ray Diffraction, Fourier transform infrared and energy-dispersive X-ray spectroscopes all indicate Al-WTR is mainly composed of amorphous aluminium which influences its phosphorus (P) adsorption capacity. The pH and electrical conductivity ranged from 5.9 to 6.0 and 0.104 dS m(-1) to 0.140 dS m(-1) respectively, showing that it should support plant growth. Batch tests showed adsorption maxima of 31.9 mg P g(-1) and significant P removal was achieved in column tests. Overall, results showed that Al-WTR can be used for P removal in engineered wetlands and it carries the benefits of reuse of a by-product that promotes sustainability.

Elicited repetitive daily blindness: a new phenotype associated with hemiplegic migraine and SCN1A mutations

OBJECTIVE

Familial hemiplegic migraine (FHM) is a genetically heterogeneous disorder in which three genes, CACNA1A, ATP1A2, and SCN1A, are currently known to be involved. FHM is occasionally associated with other neurologic symptoms such as cerebellar ataxia or epileptic seizures. A unique eye phenotype of elicited repetitive daily blindness (ERDB) has also been reported to be cosegregating with FHM in a single Swiss family.

METHODS

We report an additional family in whom the proband had, in addition to FHM, typical ERDB. In this family and the previously reported Swiss family, the whole coding region of the SCN1A gene was screened after exclusion of mutation in CACNA1A and ATP1A2 genes.

RESULTS

We identified two novel SCN1A mutations (c.4495T>C/p.Phe1499Leu and c.4467G>C/p.Gln1489His missense substitutions) in exons 24 and 23, respectively, segregating with the disease in all living affected members. Both mutations were absent from 180 healthy Caucasian controls and were located in an intracellular loop highly conserved throughout evolution.

CONCLUSION

We report new clinical data supporting cosegregation of familial hemiplegic migraine and the new eye phenotype of elicited repetitive daily blindness and two novel SCN1A mutations as the underlying genetic defect in two unrelated families. SCN1A encodes the voltage-gated sodium channel Nav1.1 that is highly expressed in the CNS including the retina. This remarkably stereotyped new eye phenotype has clinical characteristics of abnormal propagation of the retinal electrical signal that may be a retinal spreading depression. These results suggest that SCN1A mutations, which alter neuronal brain excitability, may occasionally alter retinal cell excitability.

Mesoporous silicas impregnated with cobalt and nickel oxide nanoparticles and the growth of carbon nanotubes there from

Metal oxide-based nanoparticles of cobalt or nickel were deposited inside the pores and on the surface of hexagonal mesoporous silicas by a direct synthesis technique using Pluronic P85 and P123 surfactants as structure directing agents with the appropriate metal phthalocyanine as a metal precursor. Metal loadings were between 0.4-3.2 wt.%. XPS studies showed that the initial form of the metal oxide nanoparticles were [CoO] and [NiO] respectively. Samples of these materials formed from the P85 surfactant and 3.0 wt.% were used to grow carbon nanotubes (CNTs) from acetylene feedstock in a catalytic chemical vapour deposition (CCVD) reactor at 800 degrees C. CNT growth appeared to be random and the CNTs had diameters ranging from < 10 to > 90 nm. Treatment of the metal impregnated silicas with nitric acid produced materials which, under the same CNT growth conditions, afforded more uniform CNTs with diameters between 5-15 nm. No significant loss in mesophase ordering was seen in the TEM, PXRD or nitrogen physisorption analysis of the acid washed samples. CNTs grown with cobalt impregnated silicas formed with the P123 surfactant had diameters in the range 15-25 nm. Raman spectroscopy of the CNT products showed the nanotubes were highly graphitised and of good quality.

Patient with Fanconi Syndrome (FS) and retinitis pigmentosa (RP) caused by a deletion and duplication of mitochondrial DNA (mtDNA)

BACKGROUND

We report a patient with a highly unusual presentation of a mitochondrial disorder.

HISTORY AND SIGNS

An 8-year old girl presented with muscular cramps as well as height and weight deceleration. Investigations revealed lactic acidosis, electrolytic imbalance and urinary loss of glucose and electrolytes secondary to proximal renal tubulopathy consistent with Fanconi syndrome (FS). Ophthalmic examination revealed asymptomatic retinitis pigmentosa (RP) with no other ocular manifestations. A mitochondriopathy was suspected and genetic analysis performed.

THERAPY AND OUTCOME

Southern blotting documented a heteroplasmic mutation of mtDNA with deletion/duplication. Three discrete mitochondrial genomes were detected: normal; deletion of 6.7 kb and a deletion/duplication consisting of 1 normal and 1 deleted genome. The relative proportions varied considerably between tissues.

CONCLUSIONS

The association of FS and RP combines features of Kearns-Sayre syndrome and Pearson marrow-pancreas syndrome, without being typical of either. This highly unusual clinical presentation emphasises the need for systemic investigation of patients with FS and further underlines the importance of mtDNA analysis in patients with unexpected associations of affected tissues.

The remarkable reaction of N2O with a binary component lanthanide oxide mixture

The interaction of N2O with a Sm2O3-PrO(2-x) mixed oxide proceeds via the unexpected production of a new bulk phase that has been tenatively assigned to a new cis-hyponitrite compound.

Elicited repetitive daily blindness: a new familial disorder related to migraine and epilepsy

The authors report a family affected by multiple daily episodes of transient visual loss, elicited repetitive daily blindness (ERDB); the onset was early in life, and the disease followed a benign course. ERDB is associated with childhood epilepsy and familial hemiplegic migraine, apparently segregating as a monogenic, autosomal dominant condition with variable expression. Genetic linkage to CACNA1A was excluded.

Trafficking of natural killer cells

Natural killer (NK) cells comprise a set of lymphocytes that is capable of mediating innate immune responses to viral infections, malignancies, and allogeneic bone marrow grafts. This review summarizes what is known about the mechanisms NK cells use to arrive at their sites of action. NK cells express a wide array of adhesion molecules including alphaLbeta2, alphaMbeta2, alphaXbeta2, and alpha4beta1 integrins, ICAM-1, PSGL-1, and L-selectin. Like other immune and inflammatory cells, NK cells use the blood circulation to enter tissues and organs, which requires that they interact with the vessel wall under flow conditions, arrest, and transmigrate. NK cells are able to chemotax to a variety of cytokines and chemokines, including IL-12, IFN-(alpha/beta, CCL2, 3, 4, 5, 7, 8, CXCL8, and CX3CL1. In many cases, NK cells appear to migrate towards these soluble factors without any kind of priming. These cells also appear to distribute in secondary and tertiary lymphoid sites (i.e., spleen, bone marrow, liver, lung, and lymph nodes) both with and without stimulation. In addition to their ability to move throughout the body in an unprimed state, activated NK cells may have increased specificity in homing to sites of inflammation. NK cells not only react to, but also produce IFN-gamma, TNF-alpha, GM-CSF, CCL3, CCL4, and CCL5, enabling them to recruit various immune cells to sites of immune response.

Phenotypic heterogeneity of dopa-responsive dystonia in monozygotic twins

The clinical expression of dopa-responsive dystonia (DRD) was found to be different in a pair of affected monozygotic twins. An earlier onset was associated with a more disabling course of disease. Whereas monozygosity was genetically proven, the search for pathogenic mutations in the GTP-cyclohydrolase-1 gene was negative. The contribution of environmental factors appeared minimal. Intrafamilial variability of DRD phenotype may be related to yet unknown non-Mendelian epigenetic or proteomic factors.

The synthesis of matrices of embedded semiconducting nanowires

In this work we report how single crystal nanowires can be assembled into regular arrays using mesoporous thin films to define the architecture. Mesoporous thin films were prepared by a sol-gel method. These provide films of very regular structure and dimensions. The films produced in this way have almost single crystal like structures and can also exhibit strong epitaxy to the underlying silicon substrate. The films are subjected to a supercritical fluid (SCF) environment in which a precursor is decomposed to yield nanowires of metals, semiconductors or oxides. Using these SCF conditions, pore filling is complete and the products are nanowires which are single crystals and structurally aligned in one direction. The growth mechanism of the nanowires is described and size effects discussed.

Familial predisposition to tufted angioma: identification of blood and lymphatic vascular components

Tufted angioma is a rare benign vascular lesion of unknown etiology which mainly affects children under 5 years. It is characterized by nodules or tufts of capillary-sized vessels in the dermis. Here we report the second familial occurrence of tufted angioma, with a mode of inheritance compatible with a monogenic autosomal dominant trait with reduced penetrance. A preliminary investigation was performed to exclude association between the predisposition and certain candidate genes including KDR (kinase insert domain receptor), TEK (TEK tyrosine kinase endothelial), ACVRL1 (activin receptor-like kinase 1), ENG (endoglin) and FLT4 (fms-like tyrosine kinase 4). KDR, ENG and FLT4 were all compatible with linkage, with haplotypes being shared between three affected individuals and the one obligate carrier available for testing. TEK and ACVRL1 could essentially be excluded. Finally, we provide definitive evidence for the existence of both blood and lymphatic vascular elements in the lesion.

N-acetylcysteine augments adenovirus-mediated gene expression in human endothelial cells by enhancing transgene transcription and virus entry

BACKGROUND

It has previously been shown that oxidants reduce the efficiency of adenoviral transduction in human umbilical vein endothelial cells (HUVECs). In this study, the effect of the antioxidant N-acetylcysteine (NAC) in adenovirus-mediated gene transfer has been investigated.

METHODS

HUVECs were pretreated or not with NAC, and infected with E1E3-deleted adenovirus (Ad) containing the LacZ gene expressed from the RSV-LTR promoter/enhancer in the presence and absence of NAC. Transgene expression was assessed at the protein level (histochemical staining, measurement of beta-Gal activity, and western blot), mRNA level (real-time RT-PCR) and gene level (nuclear run on) 24 h and 48 h after infection. Adenoviral DNA was quantitated by real-time PCR, and cell surface expression of Coxsackie/adenovirus receptors (CAR) was determined by FACS analysis.

RESULTS

Pretreatment of cells with NAC prior to Ad infection enhanced beta-Gal activity by two-fold due to an increase in viral DNA, which was related to increased CAR expression. When NAC was present only during the post-infection period, a five-fold increase in beta-Gal activity and LacZ gene transcriptional activity was observed. When NAC was present during both the pretreatment and the post-infection period, beta-Gal activity was further enhanced, by 15-fold. Augmentation of beta-Gal activity was paralleled by an increase in beta-Gal protein and mRNA levels. NAC did not affect the half-life of LacZ mRNA.

CONCLUSION

Pretreatment with NAC prior to Ad infection enhances virus entry, while treatment with NAC post-infection increases transgene transcription. This strategy permits the use of lower adenoviral loads and thus might be helpful for gene therapy of vascular diseases.

Synthesis and characterization of dimensionally ordered semiconductor nanowires within mesoporous silica

Semiconductor nanowires of silicon have been synthesized within the pores of mesoporous silica using a novel supercritical fluid solution-phase approach. Mesoporous silica, formed by the hydrolysis of tetramethoxysilane (TMOS) in the presence of a triblock copolymer surfactant, was employed for the nucleation and growth of quantum-confined nanowires. The filling of the silica mesopores with crystalline silicon and the anchoring of these nanowires to the sides of the pores were confirmed by several techniques including electron microscopy, powder X-ray diffraction, 29Si magic angle spinning nuclear magnetic resonance, infrared spectroscopy, and X-ray fluorescence. Effectively, the silica matrix provides a means of producing a high density of stable, well-ordered arrays of semiconductor nanowires in a low dielectric medium. The ordered arrays of silicon nanowires also exhibited discrete electronic and photoluminescence transitions that could be exploited in a number of applications, including nanodevices and interconnects.

The differential regulation of CART gene expression in a pituitary cell line and primary cell cultures of ovine pars tuberalis cells

The cocaine-amphetamine regulated transcript (CART) encodes for a protein which has an important role in the regulation of appetite and body weight. To date, no details of the molecular events and signal transduction pathways which regulate this gene are available. We report the identification of CART gene expression in the GH3 pituitary cell line. We have used activators of the cAMP or protein kinase C (PKC) signal transduction pathways to show that, in GH3 cells, CART is transcriptionally up-regulated by activators of the cAMP signal transduction pathway. We also identify CART gene expression in ovine pars tuberalis (PT) tissue and primary cell cultures. In PT cells in contrast to GH3 cells, CART gene expression is upregulated by activators of the PKC signal transduction pathway. Cultured cells have provided a valuable resource for the detailed analysis of specific regulatory mechanisms underlying transcriptional or translational regulation of genes, signal transduction events and many other cellular processes. GH3 and PT cells may therefore provide a resource for the further detailed molecular analysis of the events regulating CART gene expression and processing.

Molecular analysis of the fibrinogen gene cluster in 16 patients with congenital afibrinogenemia: novel truncating mutations in the FGA and FGG genes

Congenital afibrinogenemia is an autosomal recessive disorder characterized by the complete absence of detectable fibrinogen. We previously identified the first causative mutations for this disease in a non-consanguineous Swiss family. These were homozygous deletions of approximately 11 kb of the fibrinogen alpha chain gene (FGA). Our subsequent study revealed that the majority of cases were attributable to truncating mutations in FGA, with the most common mutation affecting the donor splice site in FGA intron 4 (IVS4+1 G-->T). Here, we report 13 further unrelated patients with mutations in FGA, confirming the relative importance of this gene compared with FGG and FGB in the molecular aetiology of afibrinogenemia. Three other patients were homozygous for mutations in FGG. Eight novel mutations were identified: five in FGA and three in FGG. Sufficient mutation data is now available to permit an effective strategy for the genetic diagnosis of congenital afibrinogenemia.

Activation of multiple cryptic donor splice sites by the common congenital afibrinogenemia mutation, FGA IVS4 + 1 G-->T

Our recent studies on the molecular basis of the autosomal recessive disorder congenital afibrinogenemia showed that the most common mutation is a donor splice mutation in FGA intron 4, IVS4 + 1 G-->T, accounting for approximately half of disease alleles. The effect of this mutation on messenger RNA (mRNA) splicing, however, remained unproven. COS-7 cells transfected with a normal plasmid construct produced 100% mRNA molecules with correct splicing, whereas cells transfected with a mutant construct produced multiple aberrant mRNAs, due to utilization of cryptic donor splice sites situated in exon 4 and intron 4. One particular site situated 4 base pairs (bp) downstream of the normal site was used in 85% of transcripts causing afibrinogenemia by a 4-bp insertion-frameshift, leading to premature alpha-chain truncation. Our results confirm the utility of transfecting COS-7 cells to study mRNA splice-site mutations and demonstrate that the common FGA IVS4 variant is a null mutation leading to afibrinogenemia.

Parental origin of the deletion 22q11.2 and brain development in velocardiofacial syndrome: a preliminary study

BACKGROUND

As children with velocardiofacial syndrome (VCFS) develop, they are at increased risk for psychopathology; one third will eventually develop schizophrenia. Because VCFS and the concomitant symptomatology result from a known genetic origin, the biological and behavioral characteristics of the syndrome provide an optimal framework for conceptualizing the associations among genes, brain development, and behavior. The purpose of this study was to investigate the effect of the parental origin of the 22q11.2 microdeletion on the brain development of children and adolescents with VCFS.

METHODS

Eighteen persons with VCFS and 18 normal control subjects were matched individually for age and sex. Results of DNA polymorphism analyses determined the parental origin of the deletion. Nine persons with VCFS had a deletion on the maternally derived chromosome 22; 9 persons, on the paternally derived chromosome 22. High-resolution magnetic resonance imaging scans were analyzed to provide quantitative measures of gray and white matter brain tissue.

RESULTS

Total brain volume was approximately 11% smaller in the VCFS group than in controls. Comparisons between VCFS subgroups (maternal vs paternal microdeletion 22q11.2) indicated a significant 9% volumetric difference in total volume of cerebral gray matter (volume was greater in patients with paternal microdeletion) but not cerebral white matter. Significant age-related changes in gray matter were detected for subjects whose 22q11.2 deletion was on the maternal chromosome.

CONCLUSIONS

Children and adolescents with VCFS experience major alterations in brain volumes. Significant reduction in gray matter development is attributable to presence of 22q11.2 microdeletion on the maternal chromosome.

A genome-wide family-based linkage study of coeliac disease

The susceptibility to develop coeliac disease (CD) has a strong genetic component, which is not entirely explained by HLA associations. Two previous genome wide linkage studies have been performed to identify additional loci outside this region. These studies both used a sib-pair design and produced conflicting results. Our aim is to identify non-MHC genetic loci contributing to coeliac disease using a family based linkage study. We performed a genome wide search in 16 highly informative multiply affected pedigrees using 400 microsatellite markers with an average spacing of 10 cM. Linkage analysis was performed using lod score and model free methods. We identified two new potential susceptibility loci with lod scores of 1.9, at 10q23.1, and 16q23.3. Significant, but lower lod scores were found for 6q14 (1.2), 11p11 (1.5), and 19q13.4 (0.9), areas implicated in a previous genome wide study. Lod scores of 0.9 were obtained for both D78507, which lies 1 cM from the gammaT-cell receptor gene, and for D2S364, which lies 12 cM from the CTLA4 gene.

Familial t(6;21)(p21.1;p13) translocation associated with male-only sterility

A 38-year-old male with primary infertility was referred for cytogenetic investigation. Karyotype analysis revealed a 46,XY,t(6;21)(p21.1;pl3) translocation. The Ag-nucleolar organizer regions (NORs) banding technique demonstrated that the 21p NORs were retained in the derivative and actively transcribed. Family studies showed that three brothers, two sisters and their mother carried the t(6;21). All carrier males suffered from primary infertility with severe oligoasthenoteratospermia or azoospermia, whereas at least two of the three carrier women were fertile. The region of the translocation breakpoint was narrowed down cytogenetically and by fluorescence in situ hybridisation as 21p13 and 6p21.1. Southern blot analysis showed that the gene ZNF165, which maps to this region and which is specifically expressed in the testis, was not disrupted by the translocation. However, studies performed on testicular biopsy showed spermatocyte meiosis anomalies. We discuss the possible mechanisms by which the translocation might affect meiosis in spermatogenesis and lead to infertility.

Breast cancer and active and passive smoking: the role of the N-acetyltransferase 2 genotype

The association of breast cancer with passive and active smoking was investigated in slow and fast acetylators of aromatic amines in a Geneva, Switzerland, study in 1996-1997. A slow acetylator was homozygous for one, or heterozygous for two, of three N-acetyltransferase 2 (NAT2) polymorphisms determined on buccal cell DNA from 177 breast cancer cases and 170 age-matched, population controls. The reference group consisted of women never regularly exposed to active or passive smoke. Among premenopausal women, the odds ratios were homogeneous in slow and fast acetylators: 3.2 (95% confidence interval (CI): 1.2, 8.7) for passive smoking and 2.9 (95% CI: 1.1, 7.5) for active smoking. Among postmenopausal women, the odds ratios for fast acetylators were 11.6 (95% CI: 2.2, 62.2) for passive and 8.2 (95% CI: 1.4, 46.0) for active smoking; the corresponding effects were also apparent but less strong in slow acetylators. After the nonexposed and the passive smokers were grouped in a single reference category, active smoking was associated with postmenopausal breast cancer in slow acetylators (odds ratio (OR) = 2.5, 95% CI: 1.0, 6.2) but not in fast acetylators (OR = 1.3, 95% CI: 0.5, 3.3). Thus, the associations of both passive and active smoking with breast cancer appear stronger in fast than in slow NAT2 genotypes. Separating passive smokers from the nonexposed impacts on the inference about a possible NAT2-smoking interaction.

Mutations in the fibrinogen aalpha gene account for the majority of cases of congenital afibrinogenemia

Congenital afibrinogenemia is a rare, autosomal, recessive disorder characterized by the complete absence of detectable fibrinogen. We previously identified the first causative mutations in a nonconsanguineous Swiss family; the 4 affected persons have homozygous deletions of approximately 11 kb of the fibrinogen alpha (FGA) gene. Haplotype data implied that these deletions occurred on distinct ancestral chromosomes, suggesting that this region may be susceptible to deletion by a common mechanism. We subsequently showed that all the deletions were identical to the base pair and probably resulted from a nonhomologous recombination mediated by 7-bp direct repeats. In this study, we have collected data on 13 additional unrelated patients to identify the causative mutations and to determine the prevalence of the 11-kb deletion. A common recurrent mutation, at the donor splice site of FGA intron 4 (IVS4 + 1 G > T), accounted for 14 of the 26 (54%) alleles. One patient was heterozygous for the previously identified deletion. Three more frameshift mutations, 2 nonsense mutations, and a second splice site mutation were also identified. Consequently, 86% of afibrinogenemia alleles analyzed to date have truncating mutations of FGA, though mutations in all 3 fibrinogen genes, FGG, FGA, and FGB, might be predicted to cause congenital afibrinogenemia.