Considerations for radiotherapy in Bloom Syndrome: A case series.

Bloom Syndrome (BS) is a genetic DNA repair disorder, caused by mutations in the BLM gene. The clinical phenotype includes growth retardation, immunodeficiency and a strong predisposition to different types of malignancies. Treatment of malignancies in BS patients with radiotherapy or chemotherapy is believed to be associated with increased toxicity, but clinical and laboratory data are lacking. We collected clinical data of two Dutch BS patients with solid tumors. Both were treated with radiotherapy before the diagnosis BS was made and tolerated this treatment well. In addition, we collected fibroblasts from BS patients to perform in vitro clonogenic survival assays to determine radiosensitivity. BS fibroblasts showed less radiosensitivity than the severely radiosensitive Artemis fibroblasts. Moreover, studies of double strand break kinetics by counting 53BP1 foci after irradiation showed similar patterns compared to healthy controls. In combination, the clinical cases and laboratory experiments are valuable information in the discussion whether radiotherapy is absolutely contraindicated in BS, which is the Case in other DNA repair syndromes like Ataxia Telangiectasia and Artemis.

Surveillance-embedded genomic outbreak resolution of methicillin-susceptible Staphylococcus aureus in a neonatal intensive care unit.

We observed an increase in methicillin-susceptible Staphylococcus aureus (MSSA) infections at a Dutch neonatal intensive care unit. Weekly neonatal MSSA carriage surveillance and cross-sectional screenings of health care workers (HCWs) were available for outbreak tracing. Traditional clustering of MSSA isolates by spa typing and Multiple-Locus Variable number tandem repeat Analysis (MLVA) suggested that nosocomial transmission had contributed to the infections. We investigated whether whole-genome sequencing (WGS) of MSSA surveillance would provide additional evidence for transmission. MSSA isolates from neonatal infections, carriage surveillance, and HCWs were subjected to WGS and bioinformatic analysis for identification and localization of high-quality single nucleotide polymorphisms, and in-depth analysis of subsets of isolates. By measuring the genetic diversity in background surveillance, we defined transmission-level relatedness and identified isolates that had been unjustly assigned to clusters based on MLVA, while spa typing was concordant but of insufficient resolution. Detailing particular subsets of isolates provided evidence that HCWs were involved in multiple outbreaks, yet it alleviated concerns about one particular HCW. The improved resolution and accuracy of genomic outbreak analyses substantially altered the view on outbreaks, along with apposite measures. Therefore, inclusion of the circulating background population has the potential to overcome current issues in genomic outbreak inference.

Multi-component meningococcal serogroup B (MenB)-4C vaccine induces effective opsonophagocytic killing in children with a complement deficiency.

Vaccination against meningococcal serogroup B is recommended for patients with a complement deficiency; however, although immunogenicity in this patient group has been shown, efficacy has not yet been established. In this study, we collected serum from children with a complement deficiency in the alternative pathway or in late terminal pathway before and after vaccination with multi-component meningococcal serogroup B (MenB)-4C. MenB-4C is a multi-component, protein-based vaccine against MenB consisting of factor H-binding protein, Neisserial heparin-binding protein, Neisserial adhesion A and outer membrane vesicles containing Porin A. We assessed the vaccine immunogenicity and vaccine-mediated protection by a whole cell enzyme-linked immunosorbent assay with Neisseria meningitidis serogroup B strains H44/76, 5/99 and NZ98/254, which shows that vaccination induced antibody titers against meningococcus. We show that the classical serum bactericidal activity assay with exogenous serum indicates the presence of vaccine-induced antibodies and capacity to activate complement-mediated pathogen lysis. However, in children with a late terminal pathway deficiency, no complement-mediated pathogen lysis was observed when autologous serum was applied in the serum bactericidal activity assay, demonstrating a lack of serum bactericidal activity in children with complement deficiencies. However, MenB-4C vaccination still induced effective complement-dependent opsonophagocytic killing against N. meningitidis serogroup B in reconstituted whole blood with autologous serum from children with an alternative pathway or late terminal pathway deficiency. These findings support the recommendation to vaccinate all complement-deficient children against MenB.

A case promoting use of ultrasound-guided sampling techniques to correctly diagnose MDR-TB in children.

A paediatric case of multidrug-resistant tuberculosis in which endo-oesophageal ultrasound-guided fine-needle aspiration using an endobronchial ultrasound-guided bronchoscope was used to collect a sample for microbial analyses is presented. In our experience, ultrasound-guided sampling techniques, both endo-oesophageal and endobronchial, can be safely used for the diagnosis of paediatric intrathoracic tuberculous lymphadenopathy in children aged 3 years. Interventional pulmonologists with experience in using these techniques should be part of the multidisciplinary team treating these patients.

Invasive group A streptococcal infection in children: clinical manifestations and molecular characterization in a French pediatric tertiary care center.

Invasive group A streptococcal (GAS) infections have a broad and evolving clinical spectrum, associated with various GAS genotypes and/or virulence factors that are only poorly described in children. We aimed to assess the clinical and molecular characteristics of invasive GAS infections in 28 children admitted from 2000 to 2007 at a large French pediatric tertiary care center. The GAS isolates were characterized molecularly by emm-typing and by the determination of the main virulence factors: speA, speB, speC, smeZ-1, ssa, sic, and silC. The median age of the children was 2.9 years. Osteoarticular infection (OAI) was the main clinical manifestation (n=15/28, 53%). emm-1 predominated (n=10/28), followed by emm-12, 3, and 4. No significant correlation was found between emm type and clinical manifestations, but emm-1 predominated in cases of OAI (n=7/15) and was associated with speA, speB, smeZ-1, and sic virulence factor genes. In this pediatric study, we describe a predominance of OAI associated with emm-1 GAS. Further larger international pediatric studies, including host immunity evaluation, are needed in order to better assess the pathogenesis of GAS infection in children.

Neonatal outcome of 937 children born after transfer of cryopreserved embryos obtained by ICSI and IVF and comparison with outcome data of fresh ICSI and IVF cycles.

BACKGROUND: To evaluate the safety of cryopreservation in combination with IVF and ICSI, prenatal diagnosis and neonatal outcome were investigated in children conceived from frozen-thawed ICSI embryos (cryo ICSI) and frozen-thawed IVF embryos (cryo IVF). Data were also compared with earlier published results from fresh ICSI and IVF embryos. METHODS: Questionnaire data and results of physical examination at 2 months of 547 cryo ICSI children and 390 cryo IVF children were compared, and these were also compared with those of infants born after transfer of fresh embryos. RESULTS: Birth characteristics were comparable for cryo ICSI and cryo IVF infants. Cryo singletons showed a trend towards higher mean birthweight compared with fresh singletons, in ICSI and IVF, reaching significance when all cryo (ICSI plus IVF) singletons were considered. Low birthweight rate according to multiplicity was comparable between the fresh and the cryo groups, in ICSI and IVF. Non-statistically significantly increased rates of de novo chromosomal anomalies (3.2%) were found in cryo ICSI fetuses/children compared with the fresh ICSI group (1.7%) (OR 1.96; 95% CI 0.92-4.14). Major malformations were more frequently observed in cryo ICSI live borns (6.4%) than in cryo IVF live borns (3.1%) (OR 2.15; 95% CI 1.10-4.20) and fresh ICSI live borns (3.4%) (OR 1.96; 95% CI 1.31-2.91). CONCLUSIONS: In cryo ICSI compared with cryo IVF, prenatal and neonatal outcome results were comparable, except for a higher major malformation rate in the cryo ICSI group. In the total cryo group compared with the total fresh group, we found a higher mean birthweight in singletons and a higher major malformation rate in live borns.

Vif is a RNA chaperone that could temporally regulate RNA dimerization and the early steps of HIV-1 reverse transcription.

HIV-1 Vif (viral infectivity factor) is associated with the assembly complexes and packaged at low level into the viral particles, and is essential for viral replication in non-permissive cells. Viral particles produced in the absence of Vif exhibit structural defects and are defective in the early steps of reverse transcription. Here, we show that Vif is able to anneal primer tRNA(Lys3) to the viral RNA, to decrease pausing of reverse transcriptase during (-) strand strong-stop DNA synthesis, and to promote the first strand transfer. Vif also stimulates formation of loose HIV-1 genomic RNA dimers. These results indicate that Vif is a bona fide RNA chaperone. We next studied the effects of Vif in the presence of HIV-1 NCp, which is a well-established RNA chaperone. Vif inhibits NCp-mediated formation of tight RNA dimers and hybridization of tRNA(Lys3), while it has little effects on NCp-mediated strand transfer and it collaborates with nucleocapsid (NC) to increase RT processivity. Thus, Vif might negatively regulate NC-assisted maturation of the RNA dimer and early steps of reverse transcription in the assembly complexes, but these inhibitory effects would be relieved after viral budding, thanks to the limited packaging of Vif in the virions.

Medical outcome of 8-year-old singleton ICSI children (born >or=32 weeks' gestation) and a spontaneously conceived comparison group.

BACKGROUND: There is little information about the long-term outcome of children born after ICSI. In this study, the eldest cohort of ICSI children worldwide, reaching the age of 8 years, was investigated at the prepubertal stage to monitor subsequent puberty and future fertility. To investigate possible health problems, a thorough medical and neurological examination was performed. METHODS: Medical outcome of 8-year-old singletons (n=150) born through ICSI (>or=32 weeks) was compared with that of 147 singletons of the same age born after spontaneous conception (SC). Information about their general health was obtained from the parents by means of a questionnaire. RESULTS: Fifteen of 150 ICSI children experienced a major congenital malformation compared with 5/147 SC children (P < 0.05). Pubertal staging was similar in both groups. Neurological examination did not show important differences between ICSI and SC children. ICSI children did not require more remedial therapy or surgery or hospitalization than SC children. CONCLUSION: Physical examination including a thorough neurological examination did not reveal important differences between the two groups. Major congenital malformations were significantly more frequent in the ICSI group. However, most of them were corrected by minor surgery. Further monitoring of these children at an older age is recommended.

A multi-centre cohort study of the physical health of 5-year-old children conceived after intracytoplasmic sperm injection, in vitro fertilization and natural conception.

BACKGROUND: Over a million children have been born from assisted conception worldwide. Newer techniques being introduced appear less and less 'natural', such as intracytoplasmic sperm injection (ICSI), but there is little information on these children beyond the neonatal period. METHODS: 540 ICSI conceived 5-year-old children from five European countries were comprehensively assessed, along with 538 matched naturally conceived children and 437 children conceived with standard IVF. RESULTS: Of the 540 ICSI children examined, 63 (4.2%) had experienced a major congenital malformation. Compared with naturally conceived children, the odds of a major malformation were 2.77 (95% CI 1.41-5.46) for ICSI children and 1.80 (95% CI 0.85-3.81) for IVF children; these estimates were little affected by adjustment for socio-demographic factors. The higher rate observed in the ICSI group was due partially to an excess of malformations in the (boys') urogenital system. In addition, ICSI and IVF children were more likely than naturally conceived children to have had a significant childhood illness, to have had a surgical operation, to require medical therapy and to be admitted to hospital. A detailed physical examination revealed no further substantial differences between the groups, however. CONCLUSIONS: Singleton ICSI and IVF 5-year-olds are more likely to need health care resources than naturally conceived children. Assessment of singleton ICSI and IVF children at 5 years of age was generally reassuring, however, we found that ICSI children presented with more major congenital malformations and both ICSI and IVF children were more likely to need health care resources than naturally conceived children. Ongoing monitoring of these children is therefore required.