A novel high-throughput molecular counting method with single base-pair resolution enables accurate single-gene NIPT.

Next-generation DNA sequencing is currently limited by an inability to accurately count the number of input DNA molecules. Molecular counting is particularly needed when accurate quantification is required for diagnostic purposes, such as in single gene non-invasive prenatal testing (sgNIPT) and liquid biopsy. We developed Quantitative Counting Template (QCT) molecular counting to reconstruct the number of input DNA molecules using sequencing data. We then used QCT molecular counting to develop sgNIPTs of sickle cell disease, cystic fibrosis, spinal muscular atrophy, alpha-thalassemia, and beta-thalassemia. The analytical sensitivity and specificity of sgNIPT was >98% and >99%, respectively. Validation of sgNIPTs was further performed with maternal blood samples collected during pregnancy, and sgNIPTs were 100% concordant with newborn follow-up.

Impact of interhospital transport on the physiologic status of very low-birth-weight infants.

OBJECTIVES: To evaluate the change in physiologic stability of very low-birth-weight (VLBW) infants following transport using TRIPS (transport risk index of physiologic stability) score as a measure of physiologic stability and compare changes in TRIPS score in groups of VLBW infants who underwent shorter versus longer transport. STUDY DESIGN: Retrospective chart review. RESULTS: Our cohort of 106 infants, 44 (41%) of whom were females, had a mean birth weight of 777 g (standard deviation [SD] 159) and median gestational age of 26 weeks (range 23 to 32 weeks). Mean weight at transfer was 1,610 g (SD 924) and mean postnatal age at transfer was 56 days (SD 45). Median time on transport was 15 minutes (range 10 to 85 minutes). All 106 transports were ground transports. Of the 106 infants, 57 (54%) had deterioration, 20 (19%) had improvement, and 29 (27%) had no change in their physiologic status during transport. Comparison of the two transport duration groups based on median transport time as a cutoff point (i.e., ≤ 15 minutes and > 15 minutes) revealed a higher proportion of infants with deterioration in their physiologic status in the prolonged transport (>15 minutes) group (65% versus 45%; p = 0.03). Temperature change, either alone or in combination with other indices, was responsible for change in TRIPS score (deterioration or improvement) in 79% of these infants. CONCLUSIONS: Interhospital transport of VLBW infants may cause deterioration in their physiologic status, the likelihood of which is increased with longer duration of transport. Better temperature regulation during interhospital transport may decrease the chances of deterioration in physiologic status of VLBW infants.

B-type natriuretic peptide levels in preterm neonates with bronchopulmonary dysplasia: a marker of severity?

RATIONALE FOR THE STUDY: B type natriuretic peptide (BNP) is a hormone released in response to stretching of the ventricular wall. The role of BNP as a biomarker of bronchopulmonary dysplasia (BPD) has not been clarified. OBJECTIVE: To determine if plasma BNP concentrations correlate with the severity of BPD. METHODS: This prospective observational case control study included 60 preterm infants (≤32 weeks); 27 infants had no/mild BPD, 19 had moderate and 14 had severe BPD. BNP levels were measured at 36 ± 2 weeks PMA or within a week of discharge home. Groups were compared using Mann-Whitney's U-test, Kruskal-Wallis, and bivariate regression. RESULTS: Median (IQR) plasma levels of BNP in infants with moderate/severe BPD infants (n = 33) were higher as compared to those with no/mild BPD (n = 27); 27.1 (12.1-43.5) pg/ml versus 9.3 (6-18.5) pg/ml; P < 0.05 (Mann Whitney U). Median (IQR) BNP levels in infants with severe BPD (n = 14), 43.5 (28.4-189) pg/ml differed significantly from levels in those with moderate (n = 19), 22.8 (10.3-27.7) pg/ml; mild (n = 16), 11.5 (6.6-44.5 pg/ml); or no (n = 11), 8.1 (5-12.6 pg/ml) BPD (P < 0.001 Kruskal-Wallis). Based on receiver operating characteristic curves, BNP > 24.4 pg/ml at 36 ± 2 weeks PMA or discharge home was 85.7% sensitive and 76.1% specific for severe BPD. CONCLUSIONS: An elevation in plasma BNP was significantly associated with severe BPD. We speculate that plasma BNP measurement in infants with BPD may aid in risk-stratification and further targeted therapies.

Pneumatoceles in infants in the neonatal intensive care unit: clinical characteristics and outcomes.

OBJECTIVE: To describe the clinical characteristics and outcomes of neonatal intensive care unit patients with a radiographic diagnosis of pneumatocele. STUDY DESIGN: Retrospective chart review. RESULTS: Our cohort (n = 27) had a gestational age of 27 ± 5 weeks, birth weight of 1038 ± 760 g, and a predominance of females (59%) and black infants (74%). All infants were ventilated at the time of diagnosis at a median age of 12 days (range: 5 to 105 days). Endotracheal cultures sent from 25 infants revealed bacteria in 20 (80%). Clinical diagnosis of pneumonia was made in 18 (67%) infants. Pneumatoceles resolved in 17 (63%) infants, but persisted in 10 (37%) infants. Compared with infants with resolution of pneumatoceles, mortality (70% versus 0%, p < 0.001), positive endotracheal cultures (100% versus 67%, p = 0.05), and clinical diagnosis of pneumonia (100% versus 47%, p = 0.005) were significantly higher in infants with persistent pneumatoceles. CONCLUSIONS: In infants with pneumatoceles, positive endotracheal culture is a frequent finding and correlates with persistence. Persistence of pneumatoceles is associated with a higher mortality.

Neonatal thyrotoxicosis presenting as persistent pulmonary hypertension.

Neonatal hyperthyroidism is a rare condition caused either by transplacental passage of thyroid-stimulating immunoglobulins from a mother with Graves' disease or by activating mutations of the thyrotropin receptors and α-subunit of G-protein. The clinical features may vary. We report a case of neonatal thyrotoxicosis in an infant born to a mother with Graves' disease, who presented with cardiorespiratory failure and persistent pulmonary hypertension (PPHN). PPHN resolved with specific antithyroid treatment and extracorporeal membrane oxygenation was not required.

Isolated ruptured appendicitis presenting as pneumatosis intestinalis in a premature neonate.

We report a novel case of ruptured appendicitis in a premature neonate which radiographically mimicked necrotizing enterocolitis with free intraperitoneal air. On exploratory laparotomy, both the large and small intestines were normal.

Staphylococcal scalded skin syndrome in a preterm newborn presenting within first 24 h of life.

A preterm neonate was noted to have diffuse blanching erythema around the mouth followed by appearance of bullous lesions on the upper back, lower neck and right scapular areas at 23 h of life. The bullae subsequently ruptured leaving an extremely tender, erythematous, denuded area of the skin, which extended over next few hours to involve most of the upper back and right shoulder regions. Nikolsky sign was positive. Clinical diagnosis of staphylococcal scalded skin syndrome was made. The throat, blood, urine and cerebrospinal fluid cultures did not yield any growth, but wound culture was positive for Staphylococcus aureus. Treatment included administration of intravenous fluids and vancomycin for 10 days. The wound area was covered with vaseline and sterile gauge dressings. On day 5 of life, epithelialisation began and was complete on the seventh day of life. She was discharged home with intact skin, without scars, on day 12 of life.

Domestic child labor.

An informal verbal survey was conducted amongst doctor colleagues to determine the prevalence of domestic child labor in this important part of the middle class, which is expected to mirror the society's social mores. Eighty-three doctors were surveyed of which 72 employed domestic servants and 61.1% of these employed children younger than 14 years of age. No association was observed between this practice and the medical specialty or work setting of the employer. A follow-up telephonic survey, after the enactment of the law prohibiting this practice, saw decreased participation and low prevalence of the practice.

Influence of soil type and extraction conditions on perchlorate analysis by ion chromatography.

Perchlorate is a stable anion that has been introduced into the environment through activities related to its production and use as a solid rocket propellant. Perchlorate is thought to transport through soils without being adsorbed; thus, for determination of perchlorate in soil, samples are typically extracted with water prior to analysis. The completeness of extraction depends on perchlorate existing as a free ion within the soil matrix. In this study, perchlorate extraction efficiency was evaluated with five soil types under two different oxygen states. For each soil, 30% (w/w) slurries were prepared and equilibrated under either oxic or anoxic conditions prior to spiking with a stock solution of sodium perchlorate, and the slurries were then maintained for 1-week or 1-month. At the end of the exposure, slurries were centrifuged and separated into aqueous and soil phases. After phase separation, the soil was washed first with deionized water and then with 50mM NaOH, producing second and third aqueous phases, respectively. Perchlorate concentrations in the three aqueous phases were determined using ion chromatography. The results obtained from this study suggest that matrix interference and signal suppression due to high conductivity have greater effects upon observed perchlorate concentrations by ion chromatography than does perchlorate interaction with soil. Thus, a single water extraction is sufficient for quantitative determination of perchlorate in soil.