Search

Budding uninhibited by benzimidazoles (BUB1) contributes to multiple mitotic processes. Here, we describe the first two patients with biallelic BUB1 germline mutations, who both display microcephaly, intellectual disability, and several patient-specific features. The identified mutations cause variable degrees of reduced total protein level and kinase activity, leading to distinct mitotic defects. Both patients’ cells show prolonged mitosis duration, chromosome segregation errors, and an overall functional spindle assembly checkpoint. However, while BUB1 levels mostly affect BUBR1 kinetochore recruitment, impaired kinase activity prohibits centromeric recruitment of Aurora B, SGO1, and TOP2A, correlating with anaphase bridges, aneuploidy, and defective sister chromatid cohesion. We do not observe accelerated cohesion fatigue. We hypothesize that unresolved DNA catenanes increase cohesion strength, with concomitant increase in anaphase bridges. In conclusion, BUB1 mutations cause a neurodevelopmental disorder, with clinical and cellular phenotypes that partially resemble previously described syndromes, including autosomal recessive primary microcephaly, mosaic variegated aneuploidy, and cohesinopathies., Description, Biallelic germline mutations in a gene important for mitotic fidelity, BUB1, are first described and functionally assessed.

A 13-year-old boy was seen with symmetric bilateral swelling around the proximal interphalangeal joints. He did not have pain or loss of function or other signs of arthritis. Inflammation parameters and rheumatologic markers were negative. X-ray and MRI revealed soft tissue swelling. This confirmed the diagnosis pachydermodactyly, a rare benign form of fibromatosis.

Objective: Angiotensin-converting enzyme and its effector peptide angiotensin II have been implicated in the pathogenesis of acute respiratory distress syndrome. Recently, angiotensin-converting enzyme 2 was identified as the counter-regulatory enzyme of angiotensin-converting enzyme that converts angiotensin II into angiotensin-(1-7). The aim of this study was to determine pulmonary angiotensin-converting enzyme and angiotensin-converting enzyme 2 activity in patients with acute respiratory distress syndrome.Design: Prospective observational pilot study.Setting: A PICU of a university hospital.Patients: Fourteen patients admitted, requiring mechanical ventilation for respiratory syncytial virus lower respiratory tract infection.Interventions: None.Measurements and Main Results: Two groups of patients were distinguished at admission: a group fulfilling the criteria for acute respiratory distress syndrome and a non-acute respiratory distress syndrome group. Angiotensin-converting enzyme and angiotensin-converting enzyme 2 activity were measured in bronchoalveolar lavage fluid. Patients with acute respiratory distress syndrome had increased angiotensin-converting enzyme activity and decreased angiotensin-converting enzyme 2 activity (p Conclusion: It is shown for the first time that in acute respiratory distress syndrome, enhanced angiotensin-converting enzyme activity is paralleled by a reduced angiotensin-converting enzyme 2 activity, similar to that found in an experimental rat model of acute respiratory distress syndrome. The reduced angiotensin-converting enzyme 2 activity may be counteracted by restoring angiotensin-(1-7) level, thereby offering a novel treatment modality for this syndrome.

Background Kawasaki disease ( KD ) is a pediatric vasculitis with coronary artery aneurysm ( CAA ) as a major complication. Controversy exists about cardiovascular risk later in life. The aim of our study was to evaluate whether KD patients are at increased risk, as assessed by carotid intima‐media thickness ( cIMT ). Methods and Results We measured cIMT over 15 years by B‐mode ultrasonography in KD patients during follow‐up and in unaffected controls (mostly siblings). A multilevel, repeated‐measures, linear mixed‐effects model was used to evaluate the association between KD and cIMT . A total of 319 patients with 528 measurements were compared with 150 controls. In KD patients, the mean cIMT was increased compared with controls (0.375 mm [95% CI 0.372–0.378 mm] versus 0.363 mm [95% CI 0.358–0.368 mm]; P cIMT of CAA ‐negative patients was 0.373 mm ( P CAA was 0.374 mm ( P CAA was 0.381 mm ( P CAA ‐negative participants started with an increased cIMT (+0.0193±0.0053 mm, P P =0.012). Patients with giant CAA showed a trend toward increased cIMT progression (0.0013±0.0007 mm/year, P =0.058). Conclusions We observed a positive correlation between cIMT and KD severity of coronary arteritis at the acute stage. Although initially increased, the cIMT in CAA ‐negative patients normalized at a later age. In contrast, patients with a history of KD complicated by giant CAA showed a trend toward persistently increased cIMT . These patients may need cardiovascular counseling and follow‐up beyond the heart.

Children with Down syndrome (DS) are at high risk for acute lung injury (ALI). Pulmonary epithelial apoptosis is an important factor in the pathophysiology of ALI. Whether the risk of ALI in DS is associated with a high level of pulmonary epithelial apoptosis is not known. We hypothesized that the percentage of apoptotic epithelial cells is higher in DS than in control lungs. Lung tissue sections from autopsies of 21 fetuses with DS and 12 controls were stained with antibodies against the epithelial marker pan-cytokeratin (CK) and apoptosis marker activated caspase-3 (aC3). Spectral imaging software was used to quantify the mean percentage of pixels that showed colocalization of CK and aC3. Mean (standard deviation [SD]) gestational age in weeks was 18.7 (1.4) in DS and 18.9 (2.0) in controls ( P = 0.67). The mean (SD) percentage of CK-positive pixels was 27.2% (4.7%) in DS compared to 27.1% (6.2%) in controls ( P = 0.97). The median (interquartile range [IQR]) percentage of CK-positive pixels that showed colocalization of aC3 was 0.16% (0.18%) in DS compared to 0.27% (0.24%) in controls ( P = 0.45). The mean (SD) number of CK-positive pixels increased from 22.5% (5.2%) to 30.4% (4.6%) with the appearance of saccular morphology in controls but not in DS ( P = 0.01). The percentage of apoptotic epithelial cells in DS fetal lungs does not differ from that in controls. However, we did find a difference in the development of epithelial structures between DS and controls that may be associated with anomalies in alveolar development found at birth in DS.

Objective: Acute respi- ratory tract infection is a common reason for hospitalization in children with Down syndrome (CDS) and is characterized by a high morbidity. The severe course of disease in CDS may be related to a higher incidence of acute lung injury (ALI). This study evaluated the incidence of ALI and acute respiratory distress syndrome (ARDS) in mechanically ventilated CDS. Design and setting: Retrospec- tive cohort study in a pediatric ICU. Patients and participants: Cases were all mechanically ventilated CDS admitted to our unit between January 1998 and July 2005. All mechanically ventilated patients without Down syn- drome from January 1998 to January 2001 served as controls. Postopera- tive patients (cases and controls) and those with a cardiac left to right shunt were excluded. Measurements and results: The main outcome measure was the incidence of ALI and ARDS. The criteria for ALI were met in 14 of 24 CDS (58.3%) in 41 of 317 of controls (12.9%; OR 9.4, 95% CI 3.9-22.6). The criteria for ARDS were met in 11 of 24 CDS (46%) and in 21 of 317 of controls (7%;OR 11.9, 95% CI 4.8-29.8). None of the CDS with ALI died; in the control group ten patients with ALI died. Conclu- sions: CDS had a significantly higher incidence of ALI and ARDS than children without Down syndrome. The explanation for this remains to be elucidated; further study is necessary before clinical implications become clear.

High plasma C-reactive protein (CRP) levels are associated with favorable outcome in adults with acute lung injury (ALI). The association between CRP levels and outcome has not been studied in ALI in children. We performed a historical cohort study in 93 mechanically ventilated children (0–18 years) with ALI. The CRP level within 48 h of disease onset was tested for association with 28-day mortality and ventilator-free days (VFD). Clinical parameters and ventilator settings were evaluated for possible confounding. Fourteen patients died within 28 days. The median (interquartile range) CRP level in nonsurvivors was 126 mg/L (64; 187) compared with 56 mg/L (20; 105) in survivors (p = 0.01). For every 10-mg/L rise in CRP level, the unadjusted odds (95 % confidence interval (95 % CI)) for mortality increased 8.7 % (2.1–15.8 %). Cardiovascular organ failure at onset of ALI was the strongest predictor for mortality (odds ratio, 30.5 (6.2–152.5)). After adjustment for cardiovascular organ failure, for every 10-mg/L rise in CRP level, the OR (95 % CI) for mortality increased 4.7 % (−2.7–12.6 %; p = 0.22). Increased CRP levels were associated with a decrease in VFD (ρ = −0.26, p = 0.01). Conclusion: increased plasma CRP levels are not associated with favorable outcome in ALI in children. This is in contrast with findings in adults with ALI.

Children with Down syndrome are at high risk for acute respiratory distress syndrome. In Down syndrome, both regulation of inflammation and apoptosis, important in acute respiratory distress syndrome pathophysiology, are abnormal. This has been linked to an imbalance in free radical scavengers. We investigated the expression of free radical scavengers and the effect of oxidative stress in terms of apoptosis and inflammation in respiratory epithelium from children with Down syndrome compared with control subjects. We cultured primary nasal epithelial cells from Down syndrome children (n=12) and controls (n=17) and exposed them to oxidative stress by supplementing superoxide. First we showed that the expression of the free radical scavengers CuZn-superoxide dismutase was 28% higher (p=0.06), catalase was 36% lower (p=0.04) and glutathione peroxidase was 73% lower (p=0.004) in Down syndrome children compared with controls. We found no significant difference in apoptosis, between Down syndrome and control subjects after exposure to oxidative stress. We also found no significant difference in levels of interleukin (IL)-1β, IL-6, IL-8, vascular endothelial growth factor and granulocyte colony-stimulating factor in primary nasal epithelial cell supernatant after exposure to oxidative stress between Down syndrome and control subjects. We found an imbalance in free radical scavengers in respiratory epithelial cells from children with Down syndrome, but this did not result in increased levels of either apoptosis or inflammation upon exposure to oxidative stress.

Lower respiratory tract infection by respiratory syncytial virus (RSV) is a frequent cause of acute lung injury in young children and infants. Studies in adults and animals suggest that tumor necrosis factor receptor (TNFR) ligands may mediate lung injury by causing apoptosis of epithelial cells. The main goal of the present study was to determine whether the TNF-related apoptosis-inducing ligand (Apo2L/TRAIL) pathway may be implicated in epithelial injury during severe RSV infection in children. We report elevated levels of soluble (s)TRAIL released by leukocytes in bronchoalveolar lavage fluid (BALF) of patients with RSV-associated respiratory failure (n = 22) as compared with mechanically ventilated patients without pulmonary illness (n = 7). Primary bronchial epithelial cells of children without pulmonary disease obtained by nonbronchoscopic cytobrushing expressed both death receptors TRAIL-R1 and -R2, and were found to be susceptible for cell death by human recombinant sTRAIL in vitro. Furthermore, BALF from a patient with RSV induced cell death in these cells, which was partly attenuated by inhibiting TRAIL signaling. These data suggest that the TRAIL pro-apoptotic pathway may contribute to lung epithelial injury in severe RSV infection in children.