MAP2K1-Mutated Melanocytic Neoplasms With a SPARK-Like Morphology.

ABSTRACT: Specific alterations involving MAPK genes (MAP3K8 fusions, MAP3K3 fusions) have been recently detected in a subgroup of spitzoid neoplasms that seem to constitute a distinctive clinicopathologic group, occur mostly in younger patients (median age 18 years) and present with atypical histologic features associated with frequent homozygous deletion of CDKN2A, qualifying a high proportion of them as Spitz melanoma (malignant Spitz tumor). Apart from lesions with spitzoid morphology harboring MAP3K8 or MAP3K3 fusion, a single case with MAP2K1 deletion has been identified. The authors report herein 4 melanocytic lesions with a MAP2K1 mutation, all showing similar microscopic appearances, including spitzoid cytology and dysplastic architectural features, resembling so-called SPARK nevus, suggesting that these lesions may represent another distinctive group.

Pre- and postnatal growth failure with microcephaly due to two novel heterozygous IGF1R mutations and response to growth hormone treatment.

AIM: To explore the phenotype and response to growth hormone in patients with heterozygous mutations in the insulin-like growth factor I receptor gene (IGF1R). METHODS: Children with short stature, microcephaly, born SGA combined with biochemical sign of IGF-I insensitivity were analysed for IGF1R mutations or deletions using Sanger sequencing and Multiple ligation-dependent probe amplification analysis. RESULTS: In two families, a novel heterozygous non-synonymous missense IGF1R variant was identified. In family 1, c.3364G > T, p.(Gly1122Cys) was found in the proband and co-segregated perfectly with the phenotype in three generations. In family 2, a de novo variant c.3530G > A, p.(Arg1177His) was detected. Both variants were rare, not present in the GnomAD database. Three individuals carrying IGF1R mutations have received rhGH treatment. The average gain in height SDS during treatment was 0.42 (range: 0.26-0.60) and 0.64 (range: 0.32-0.86) after 1 and 2 years of treatment, respectively. CONCLUSION: Our study presents two heterozygous IGF1R mutations causing pre- and postnatal growth failure and microcephaly and also indicates that individuals with heterozygous IGF1R mutations can respond to rhGH treatment. The findings highlight that sequencing of the IGF1R should be considered in children with microcephaly and short stature due to pre- and postnatal growth failure.

Genetic screening in sudden cardiac death in the young can save future lives.

BACKGROUND: Autopsy of sudden cardiac death (SCD) in the young shows a structurally and histologically normal heart in about one third of cases. Sudden death in these cases is believed to be attributed in a high percentage to inherited arrhythmogenic diseases. The purpose of this study was to investigate the value of performing post-mortem genetic analysis for autopsy-negative sudden unexplained death (SUD) in 1 to 35 year olds. METHODS AND RESULTS: From January 2009 to December 2011, samples from 15 cases suffering SUD were referred to the Department of Clinical Genetics, Umeå University Hospital, Sweden, for molecular genetic evaluation. PCR and bidirectional Sanger sequencing of genes important for long QT syndrome (LQTS), short QT syndrome (SQTS), Brugada syndrome type 1 (BrS1), and catecholaminergic polymorphic ventricular tachycardia (CPVT) (KCNQ1, KCNH2, SCN5A, KCNE1, KCNE2, and RYR2) was performed. Multiplex ligation-dependent probe amplification (MLPA) was used to detect large deletions or duplications in the LQTS genes. Six pathogenic sequence variants (four LQTS and two CPVT) were discovered in 15 SUD cases (40%). Ten first-degree family members were found to be mutation carriers (seven LQTS and three CPVT). CONCLUSION: Cardiac ion channel genetic testing in autopsy-negative sudden death victims has a high diagnostic yield, with identification of the disease in 40 of families. First-degree family members should be offered predictive testing, clinical evaluation, and treatment with the ultimate goal to prevent sudden death.

Hyperglycemia in Acutely Ill Non-diabetic Children in the Emergency Rooms of 2 Tertiary Hospitals in Lagos, Nigeria.

OBJECTIVES: The study aimed to determine the prevalence of hyperglycemia in sick children admitted into the emergency rooms and to investigate its relationship with adverse outcomes. METHODS: A prospective study involving 2 tertiary hospitals in Lagos. Study subjects included all children aged beyond 1 month. An Accu-Chek Active glucometer was used for the bedside blood glucose determination. Hyperglycemia was defined as blood glucose greater than 7.8 mmol/L. RESULTS: A total of 1045 patients were recruited with hyperglycemia being recorded in 135 patients (prevalence rate of 12.9%). Mean age of the hyperglycemic patients was 29.0 ± 31.23 months. Prevalence rates of hyperglycemia among the leading diagnoses were 17.4% in acute respiratory tract infections, 11% in malaria, 15.3% in septicemia, 14.9% in gastroenteritis, and 18.2% in burns. Other conditions include sickle cell anemia, meningitis, and malnutrition. Mortality rate was significantly higher overall in hyperglycemic compared with the normoglycemic patients (15.4% vs 8.0%, P = 0.011). With regard to specific diagnoses, significantly higher mortality rates were recorded in hyperglycemic patients with acute respiratory tract infections (28% vs 8%, P = 0.011) and malaria (21.4% vs 5.0%, P = 0.006) than in their normoglycemic counterparts. CONCLUSIONS: Hyperglycemia is common in ill children admitted to the emergency rooms and is associated with 2 to 4 times higher mortality in common childhood diseases encountered. Blood glucose determination is important in all acutely ill children at presentation. The practice of empirical administration of intravenous glucose in some resource-constrained facilities where blood glucose testing facilities are not readily available should be discouraged.

Growth hormone (GH) dose-dependent IGF-I response relates to pubertal height gain.

BACKGROUND: Responsiveness to GH treatment can be estimated by both growth and ∆IGF-I. The primary aim of the present study was to investigate if mimicking the physiological increase during puberty in GH secretion, by using a higher GH dose could lead to pubertal IGFs in short children with low GH secretion. The secondary aim was to explore the relationship between IGF-I, IGFBP-3 and the IGF-I/IGFBP-3 ratio and gain in height. METHODS: A multicentre, randomized, clinical trial (TRN88-177) in 104 children (90 boys), who had received GH 33 µg/kg/day during at least 1 prepubertal year. They were followed from GH start to adult height (mean, 7.5 years; range, 4.6-10.7). At onset of puberty, children were randomized into three groups, to receive 67 µg/kg/day (GH(67)) given once (GH(67x1); n = 30) or divided into two daily injection (GH(33x2); n = 36), or to remain on a single 33 µg/kg/day dose (GH(33x1); n = 38). The outcome measures were change and obtained mean on-treatment IGF-I(SDS), IGFBP3(SDS) and IGF-I/IGFBP3 ratio(SDS) during prepuberty and puberty. These variables were assessed in relation to prepubertal, pubertal and total gain in heightSDS. RESULTS: Mean prepubertal increases 1 year after GH start were: 2.1 IGF-I(SDS), 0.6 IGFBP3(SDS) and 1.5 IGF-I/IGFBP3ratio(SDS). A significant positive correlation was found between prepubertal ∆IGFs and both prepubertal and total gain in height(SDS). During puberty changes in IGFs were GH dose-dependent: mean pubertal level of IGF-I(SDS) was higher in GH(67) vs GH(33) (p = 0.031). First year pubertal ∆IGF-I(SDS) was significantly higher in the GH(67)vs GH(33) group (0.5 vs -0.1, respectively, p = 0.007), as well as ∆IGF-I(SDS) to the pubertal mean level (0.2 vs -0.2, p = 0.028). In multivariate analyses, the prepubertal increase in '∆IGF-I(SDS) from GH start' and the 'GH dose-dependent pubertal ∆IGF-I(SDS)' were the most important variables for explaining variation in prepubertal (21 %), pubertal (26 %) and total (28 %) gain in height(SDS). TRIAL REGISTRATION: TRN 88-177, not applicable 1988. CONCLUSION: The dose-dependent change in IGFs was related to a dose-dependent pubertal gain in height(SDS). The attempt to mimic normal physiology by giving a higher GH dose during puberty was associated with both an increase in IGF-I and a dose-dependent gain in height(SDS).

Country-based reference values and international comparisons of clitoral size in healthy Nigerian newborn infants.

AIM: Clitoral size references are useful for diagnosing genital abnormalities. Despite the fact that examining the genitalia is an important aspect of newborn evaluation, few studies have been carried out to determine normal clitoral size in newborn infants. The aim of this study was to establish reference values for clitoral size in Nigerian newborn girls and to compare them with references from other ethnic populations. METHODS: A total of 244 healthy newborn girls delivered at 28-43 weeks gestation were enrolled in the study, and clitoral lengths and widths were measured at <72 hours. RESULTS: The mean clitoral length was 7.7 mm with a standard deviation of ±1.37 mm, while the mean clitoral width was 4.40 ± 0.89 mm. The clitoral length was significantly longer than those reported for Caucasian (4.00 ± 1.24 mm), Korean (3.82 ± 1.47), Turkish (4.93 ± 1.61) and Japanese (4.30 ± 1.10) babies. CONCLUSION: The present results make it possible to evaluate clitoral size in Nigerian newborn baby girls in an objective way, to identify genital abnormalities and endocrine disorders. Based on this study, a clitoral length of more than 10 mm would be considered clitoromegaly in a newborn girl in Nigeria.

Reduced morbidity at diagnosis and improved glycemic control in children previously enrolled in DiPiS follow-up.

AIMS/HYPOTHESIS: Children participating in longitudinal type 1 diabetes prediction studies were reported to have less severe disease at diabetes diagnosis. Our aim was to investigate children who from birth participated in the Diabetes Prediction in Skåne (DiPiS) study for metabolic status at diagnosis and then continued to be followed for 2 yr of regular clinical care. METHODS: Children, followed in DiPiS before diagnosis, were compared to children in the same birth cohort, who did not participate in follow-up. Metabolic status, symptoms at diagnosis as well as hemoglobin A1c (HbA1c) and doses of insulin at 3, 6, 12, and 24 months after diagnosis were compared. RESULTS: Children, followed in DiPiS and diagnosed at 2-12 yr of age, had 0.8% (9 mmol/mol) lower HbA1c at diagnosis than those who were not followed (p = 0.006). At diagnosis, fewer DiPiS children had symptoms (p = 0.014) and ketoacidosis at diagnosis were reduced (2% compared to 18%, p = 0.005). During regular clinical care, HbA1c levels for the DiPiS children remained lower both at 12 (0.4% (4 mmol/mol); p = 0.009) and 24 months (0.8% (9 mmol/mol) p < 0.001) after diagnosis, despite no difference in total daily insulin between the two groups. CONCLUSIONS: Participation in prospective follow-up before diagnosis of type 1 diabetes leads to earlier diagnosis with fewer symptoms, decreased incidence of ketoacidosis as well as better metabolic control up to 2 yr after diagnosis. Our data indicate that metabolic control at the time of diabetes diagnosis is important for early metabolic control possibly affecting the risk of long-term complications.

A missense mutation in the aggrecan C-type lectin domain disrupts extracellular matrix interactions and causes dominant familial osteochondritis dissecans.

Osteochondritis dissecans is a disorder in which fragments of articular cartilage and subchondral bone dislodge from the joint surface. We analyzed a five-generation family in which affected members had autosomal-dominant familial osteochondritis dissecans. A genome-wide linkage analysis identified aggrecan (ACAN) as a prime candidate gene for the disorder. Sequence analysis of ACAN revealed heterozygosity for a missense mutation (c.6907G > A) in affected individuals, resulting in a p.V2303M amino acid substitution in the aggrecan G3 domain C-type lectin, which mediates interactions with other proteins in the cartilage extracellular matrix. Binding studies with recombinant mutated and wild-type G3 proteins showed loss of fibulin-1, fibulin-2, and tenascin-R interactions for the V2303M protein. Mass spectrometric analyses of aggrecan purified from patient cartilage verified that V2303M aggrecan is produced and present in the tissue. Our results provide a molecular mechanism for the etiology of familial osteochondritis dissecans and show the importance of the aggrecan C-type lectin interactions for cartilage function in vivo.

Changes in mortality and causes of death in the Swedish Down syndrome population.

During the past few decades age at death for individuals with Down syndrome (DS) has increased dramatically. The birth frequency of infants with DS has long been constant in Sweden. Thus, the prevalence of DS in the population is increasing. The aim of the present study was to analyze mortality and causes of death in individuals with DS during the period 1969-2003. All individuals with DS that died between 1969 and 2003 in Sweden, and all individuals born with DS in Sweden between 1974 and 2003 were included. Data were obtained from the Swedish Medical Birth Register, the Swedish Birth Defects Register, and the National Cause of Death Register. Median age at death has increased by 1.8 years per year. The main cause of death was pneumonia. Death from congenital heart defects decreased. Death from atherosclerosis was rare but more frequent than reported previously. Dementia was not reported in any subjects with DS before 40 years of age, but was a main or contributing cause of death in 30% of the older subjects. Except for childhood leukemia, cancer as a cause of death was rare in all age groups. Mortality in DS, particularly infant mortality, has decreased markedly during the past decades. Median age at death is increasing and is now almost 60 years. Death from cancer is rare in DS, but death from dementia is common.

Glucose tolerance and beta-cell function in islet autoantibody-positive children recruited to a secondary prevention study.

AIMS: Children with type 1 diabetes (T1D) risk and islet autoantibodies are recruited to a secondary prevention study. The aims were to determine metabolic control in relation to human leukocyte antigen (HLA) genetic risk and islet autoantibodies in prepubertal children. METHODS: In 47 healthy children with GADA and at least one additional islet autoantibody, intravenous glucose tolerance test (IvGTT) and oral glucose tolerance test (OGTT) were performed 8-65 d apart. Hemoglobin A1c, plasma glucose as well as serum insulin and C-peptide were determined at fasting and during IvGTT and OGTT. RESULTS: All children aged median 5.1 (4.0-9.2) yr had autoantibodies to two to six of the beta-cell antigens GAD65, insulin, IA-2, and the three amino acid position 325 variants of the ZnT8 transporter. In total, 20/47 children showed impaired glucose metabolism. Decreased (≤ 30 µU/mL insulin) first-phase insulin response (FPIR) was found in 14/20 children while 11/20 had impaired glucose tolerance in the OGTT. Five children had both impaired glucose tolerance and FPIR ≤ 30 µU/mL insulin. Number and levels of autoantibodies were not associated with glucose metabolism, except for an increased frequency (p = 0.03) and level (p = 0.01) of ZnT8QA in children with impaired glucose metabolism. Among the children with impaired glucose metabolism, 13/20 had HLA-DQ2/8, compared to 9/27 of the children with normal glucose metabolism (p = 0.03). CONCLUSION: Secondary prevention studies in children with islet autoantibodies are complicated by variability in baseline glucose metabolism. Evaluation of metabolic control with both IvGTT and OGTT is critical and should be taken into account before randomization. All currently available autoantibody tests should be analyzed, including ZnT8QA.

The cost-effectiveness of growth hormone replacement therapy (Genotropin®) in hypopituitary adults in Sweden.

BACKGROUND: To evaluate the cost-effectiveness of growth hormone (GH) treatment (Genotropin®) compared with no GH treatment in adults with GH deficiency in a Swedish societal setting. METHODS: A Markov-type cost-utility simulation model was constructed and used to simulate, for men and women, morbidity and mortality for GH-treated and -untreated individuals over a 20-year period. The calculations were performed using current available prices concerning morbidity-related healthcare costs and costs for Genotropin®. All costs and treatment effects were discounted at 3%. Costs were expressed in Euro (1€ = 9.03 SEK). GH-treated Swedish patients (n = 434) were identified from the KIMS database (Pfizer International Metabolic Database) and untreated patients (n = 2135) from the Swedish Cancer Registry and the Hospital Discharge Registry. RESULTS: The results are reported as incremental cost per quality-adjusted life year (QALY) gained, including both direct and indirect costs for GH-treated versus untreated patients. The weighted sum of all subgroup incremental cost per QALY was €15,975 and €20,241 for men and women, respectively. Including indirect cost resulted in lower cost per QALY gained: €11,173 and €10,753 for men and women, respectively. Key drivers of the results were improvement in quality of life, increased survival, and intervention cost. CONCLUSIONS: The incremental cost per QALY gained is moderate when compared with informal thresholds applied in Sweden. The simulations suggest that GH-treatment is cost-effective for both men and women at the €55,371 (SEK 500,000 - the informal Swedish cost-effectiveness threshold) per QALY threshold.

Founder mutations characterise the mutation panorama in 200 Swedish index cases referred for Long QT syndrome genetic testing.

BACKGROUND: Long QT syndrome (LQTS) is an inherited arrhythmic disorder characterised by prolongation of the QT interval on ECG, presence of syncope and sudden death. The symptoms in LQTS patients are highly variable, and genotype influences the clinical course. This study aims to report the spectrum of LQTS mutations in a Swedish cohort. METHODS: Between March 2006 and October 2009, two hundred, unrelated index cases were referred to the Department of Clinical Genetics, Umeå University Hospital, Sweden, for LQTS genetic testing. We scanned five of the LQTS-susceptibility genes (KCNQ1, KCNH2, SCN5A, KCNE1, and KCNE2) for mutations by DHPLC and/or sequencing. We applied MLPA to detect large deletions or duplications in the KCNQ1, KCNH2, SCN5A, KCNE1, and KCNE2 genes. Furthermore, the gene RYR2 was screened in 36 selected LQTS genotype-negative patients to detect cases with the clinically overlapping disease catecholaminergic polymorphic ventricular tachycardia (CPVT). RESULTS: In total, a disease-causing mutation was identified in 103 of the 200 (52%) index cases. Of these, altered exon copy numbers in the KCNH2 gene accounted for 2% of the mutations, whereas a RYR2 mutation accounted for 3% of the mutations. The genotype-positive cases stemmed from 64 distinct mutations, of which 28% were novel to this cohort. The majority of the distinct mutations were found in a single case (80%), whereas 20% of the mutations were observed more than once. Two founder mutations, KCNQ1 p.Y111C and KCNQ1 p.R518*, accounted for 25% of the genotype-positive index cases. Genetic cascade screening of 481 relatives to the 103 index cases with an identified mutation revealed 41% mutation carriers who were at risk of cardiac events such as syncope or sudden unexpected death. CONCLUSION: In this cohort of Swedish index cases with suspected LQTS, a disease-causing mutation was identified in 52% of the referred patients. Copy number variations explained 2% of the mutations and 3 of 36 selected cases (8%) harboured a mutation in the RYR2 gene. The mutation panorama is characterised by founder mutations (25%), even so, this cohort increases the amount of known LQTS-associated mutations, as approximately one-third (28%) of the detected mutations were unique.

The metabolic consequences of thyroxine replacement in adult hypopituitary patients.

The metabolic consequences of thyroxine replacement in patients with central hypothyroidism (CH) need to be evaluated. The aim was to examine the outcome of thyroxine replacement in CH. Adult hypopituitary patients (n = 1595) with and without CH from KIMS (Pfizer International Metabolic Database) were studied before and after 2 years of GH replacement. CH patients (CH, n = 1080) were compared with TSH sufficient patients (TSHsuff n = 515) as one group and divided by thyroxine dose/kg/day into tertiles (CHlow-mid-high). Anthropometry, fasting glucose, glycosylated haemoglobin (HbA1c), blood pressure, lipids, IGF-I SDS, quality of life and morbidity were studied. Analyses were standardized for gender, age, number and types of pituitary insufficiencies, stimulated GH peak, age at GH deficiency onset, aetiologies and, when appropriate, for weight and GH dose. At baseline, TSHsuff patients did not differ from CH or CHmid in any outcome. CHlow (≤ 1.18 µg thyroxine/kg/day) had increased weight, BMI and larger waist circumference (WC), CHhigh (≥ 1.58 µg thyroxine/kg/day) had lower weight, BMI, WC and IGF-I than TSHsuff and compared to their predicted weights, BMIs and WCs. For every 0.1 µg/kg/day increase of thyroxine dose, body weight decreased 1.0 kg, BMI 0.3 kg/m(2), and WC 0.65 cm. The GH sensitivity of the CH group was higher (0.76 ± 0.56 SDS/mg GH) than that of TSHsuff patients (0.58 ± 0.64 SDS/mg GH), P < 0.001. The middle thyroxine dose (1.19-1.57 µg/kg/day) seems to be the most physiological. This is equivalent to 70, 100, 125 µg thyroxine/day for hypopituitary patients of 50, 70 or 90 kg weight, respectively.

Growth of the Kalahari Desert's bushman--the Ju/'hoansi San.

AIM: The Ju/'hoansi San (JHS) of the Kalahari Desert are the archetype of a hunter-gatherer society that practices natural fertility, living on a rich diet in a harsh environs. METHODS: To explore the evolutionary adaptation of child growth under such conditions, the present study takes a life history approach and compares the growth data of 140 JHS females and 126 JHS males age 1-25 to those in 3rd percentile American and Swedish references. The data are based on observations of the JHS that were made in 1967-1969. RESULTS: During infancy, the JHS boys lose 1.5 SDS and girls - 0.3 SDS in terms of Swedish reference. The height SDS of the JHS did not change significantly during their childhood, but growth deceleration during the juvenile period (middle childhood) was substantially greater and longer, amounting to a loss of 1.6 SDS for both girls and boys. Adolescent spurt was substantially later and smaller than that of the short-statured Americans. CONCLUSIONS: The results suggest that the short stature of the JHS is mostly established during juvenility, in adaptation to their unique living conditions.

GH deficiency during the transition period: clinical characteristics before and after GH replacement therapy in two different subgroups of patients.

OBJECTIVE: To study two subsets of patients with GH deficiency (GHD) during the transition period: childhood onset GHD (CO-GHD) and patients who develop GHD during the transition phase (TO-GHD) before and after GH replacement. PATIENTS AND MEASUREMENTS: In 1340 GHD subjects from KIMS (Pfizer International Metabolic Database), CO (n=586) or TO (n=754), background characteristics, anthropometric measurements, IGF-1, lipids and quality of life (QoL) were evaluated at baseline and after 3 years of GH replacement. RESULTS: Both groups responded similarly to GH treatment. Changes of clinical outcomes were mainly determined by their value at baseline. Onset of the disease in childhood or transition period did not appear to be a significant predictor of response in any of the clinical outcomes. CONCLUSIONS: Age at GHD diagnosis was a significant predictor for many outcomes at baseline, but disease onset did not appear as an independent predictor concerning changes after 3 years of GH treatment. The results suggest that GH replacement during the transition period should be considered independently of the onset of the deficiency.

Interactive video retrieval evaluation at a distance: comparing sixteen interactive video search systems in a remote setting at the 10th Video Browser Showdown.

The Video Browser Showdown addresses difficult video search challenges through an annual interactive evaluation campaign attracting research teams focusing on interactive video retrieval. The campaign aims to provide insights into the performance of participating interactive video retrieval systems, tested by selected search tasks on large video collections. For the first time in its ten year history, the Video Browser Showdown 2021 was organized in a fully remote setting and hosted a record number of sixteen scoring systems. In this paper, we describe the competition setting, tasks and results and give an overview of state-of-the-art methods used by the competing systems. By looking at query result logs provided by ten systems, we analyze differences in retrieval model performances and browsing times before a correct submission. Through advances in data gathering methodology and tools, we provide a comprehensive analysis of ad-hoc video search tasks, discuss results, task design and methodological challenges. We highlight that almost all top performing systems utilize some sort of joint embedding for text-image retrieval and enable specification of temporal context in queries for known-item search. Whereas a combination of these techniques drive the currently top performing systems, we identify several future challenges for interactive video search engines and the Video Browser Showdown competition itself.

Long-term response to GH therapy in short children with a delayed infancy-childhood transition (DICT).

Transition of growth from infancy to childhood is associated with activation of the GH-IGF-I axis. Children with a delayed infancy-childhood transition (DICT) are short as adults. Thus, age at ICT may impact on growth response to GH. The objective was to investigate associations between growth response to GH treatment and ICT timing in children with idiopathic short stature (ISS) in a randomized, controlled, multicenter trial, TRN 88-080. A total of 147 prepubertal children (mean age, 11.5 ± 1.4 y) were randomized to receive GH 33 µg/kg/d (GH33, n = 43), GH 67 µg/kg/d (GH67, n = 61), or no treatment (n = 43). Data on growth to final height (FH) were analyzed after categorization into those with normal (n = 76) or delayed ICT (n = 71). Within the GH33 group, significant height gain at FH was only observed in children with a DICT (p < 0.001), with each month of delay corresponding to gain of 0.13 SD score (SDS). For the GH67 group, the timing of the onset of the ICT had no impact on growth response. In conclusion, ISS children with a DICT responded to standard GH dose (better responsiveness), whereas those with a normal ICT required higher doses to attain a significant height gain to FH.

International trends of Down syndrome 1993-2004: Births in relation to maternal age and terminations of pregnancies.

BACKGROUND: The aim of this study was to examine trends of Down syndrome (DS) in relation to maternal age and termination of pregnancies (ToP) in 20 registries of the International Clearinghouse for Birth Defects Surveillance and Research (ICBDSR). METHODS: Trends of births with DS (live-born and stillborn), ToP with DS, and maternal age (percentage of mothers older than 35 years) were examined by year over a 12-year period (1993-2004). The total mean number of births covered was 1550,000 annually. RESULTS: The mean percentage of mothers older than 35 years of age increased from 10.9% in 1993 to 18.8% in 2004. However, a variation among the different registers from 4-8% to 20-25% of mothers >35 years of age was found. The total mean prevalence of DS (still births, live births, and ToP) increased from 13.1 to 18.2/10,000 births between 1993 and 2004. The total mean prevalence of DS births remained stable at 8.3/10,000 births, balanced by a great increase of ToP. In the registers from France, Italy, and the Czech Republic, a decrease of DS births and a great increase of ToP was observed. The number of DS births remained high or even increased in Canada Alberta, and Norway during the study period. CONCLUSIONS: Although an increase in older mothers was observed in most registers, the prevalence of DS births remained stable in most registers as a result of increasing use of prenatal diagnostic procedures and ToP with DS.

Influence of test weighing before/after nursing on breastfeeding in preterm infants.

PURPOSE: Swedish hospitals apply various regimens for preterm infants' nutrition in connection with their mothers' establishment of breastfeeding. Milk intake is assessed either by test weighing before and after breastfeeding or by observing the infant's suckling behavior (ie, clinical indices). These differing policies may lead to differences in infants' feeding progress. The purpose of this study was to compare effects on breastfeeding and weight gain of preterm infants, depending on whether the volume of breast milk intake when suckled in the hospital was estimated by "clinical indices" or determined by test weighing. SUBJECTS: Sixty-four infants treated at a unit applying test weighing were compared with 59 infants treated at a unit assessing milk intake by "clinical indices." DESIGN AND METHODS: A retrospective, descriptive, and comparative design was used to explore the consequences of different nutrition regimens. Data were obtained from a review of hospital medical records. PRINCIPAL RESULTS: The infants treated at the hospital where test weighing was practiced attained exclusive breastfeeding at an earlier postmenstrual age (PMA) and were also discharged at an earlier PMA. However, the 2 study units were alike regarding the proportion of infants attaining exclusive breastfeeding, the postnatal age when this occurred, and the weight pattern in hospital. CONCLUSION: To establish breastfeeding in preterm infants, test weighing before and after breastfeeding and gradual reduction of supplementation are both applicable regimens. Mothers can be encouraged to choose either of them, although test weighing may help infants attain exclusive breastfeeding at an earlier PMA.

NV-tree: an efficient disk-based index for approximate search in very large high-dimensional collections.

Over the last two decades, much research effort has been spent on nearest neighbor search in high-dimensional data sets. Most of the approaches published thus far have, however, only been tested on rather small collections. When large collections have been considered, high-performance environments have been used, in particular systems with a large main memory. Accessing data on disk has largely been avoided because disk operations are considered to be too slow. It has been shown, however, that using large amounts of memory is generally not an economic choice. Therefore, we propose the NV-tree, which is a very efficient disk-based data structure that can give good approximate answers to nearest neighbor queries with a single disk operation, even for very large collections of high-dimensional data. Using a single NV-tree, the returned results have high recall but contain a number of false positives. By combining two or three NV-trees, most of those false positives can be avoided while retaining the high recall. Finally, we compare the NV-tree to Locality Sensitive Hashing, a popular method for epsilon-distance search. We show that they return results of similar quality, but the NV-tree uses many fewer disk reads.