Dexmedetomidine versus fentanyl for sedation in extremely preterm infants.

BACKGROUND: Few studies have compared the efficacy and complications of dexmedetomidine (DEX) and fentanyl (FEN) in extremely preterm infants. METHODS: We conducted a single-institution, retrospective controlled before and after study of preterm infants before 28 weeks of gestation admitted between April 2010 and December 2018 to compare the complications and efficacy of DEX and FEN for preterm infants. Patients were administered FEN prior to 2015 and DEX after 2015 as the first-line sedative. A composite outcome of death during hospitalization and developmental quotient (DQ) < 70 at a corrected age of 3 years was compared as the primary outcome. Secondary outcomes including postmenstrual weeks at extubation, days of age when full enteral feeding was achieved and additional sedation by phenobarbital (PB) were compared. RESULTS: Sixty-six infants were enrolled into the study. The only perinatal factor that differed between the FEN (n = 33) and DEX (n = 33) groups was weeks of gestation. The composite outcome of death and DQ < 70 at a corrected age of 3 years were not significantly different. Postmenstrual weeks at extubation did not significantly differ between groups after adjustment for weeks of gestation and being small for gestational age. On the other hand, full feeding was significantly prolonged by DEX (p = 0.031). Additional sedation was less common in the DEX group (p = 0.044). CONCLUSION: The composite outcome of death and DQ < 70 at a corrected age of 3 years were not significantly different by DEX or FEN for primary sedation. Prospective randomized controlled trials should examine the long-term effects on development.

Pulmonary hypertension with bronchopulmonary dysplasia: Aichi cohort study.

BACKGROUND: The incidence of pulmonary hypertension (PH) associated with bronchopulmonary dysplasia (BPD) has not been investigated in regional cohorts. The aim of this study was to clarify the incidence of PH associated with BPD in all very low birthweight infants (VLBWIs) born during the study period in Aichi Prefecture, Japan. METHODS: We conducted a retrospective observational cohort study of all VLBWIs born in Aichi Prefecture. The inclusion criteria were VLB, birth between 1 January 2015 and 31 December 2015, and admission to any neonatal intensive care unit in Aichi Prefecture. BPD28d and BPD36w were defined as the need for supplemental oxygen or any respiratory support at 28 days of age or 36 weeks of postmenstrual age (PMA). The primary outcome was the incidence of PH after 36 weeks' PMA (PH36w) in VLBWIs with BPD28d and BPD36w. The secondary outcomes were the clinical factors related to PH36w in BPD36w patients. Mann-Whitney U-test and Fisher's exact test were used for univariate analysis. Differences were considered statistically significant at P < 0.05. Risk ratio (RR) and 95% confidence interval (CI) were also evaluated. RESULTS: A total of 441 patients were analyzed. A total of 217 and 131 patients met the definition of BPD28d and BPD36w, respectively. Nine patients were diagnosed with PH36w (4.2% and 6.9% of the BPD28d and BPD36w patients, respectively). The presence of oligohydramnios (RR, 2.71; 95% CI: 1.55-4.73, P = 0.014) and sepsis (RR, 3.62; 95% CI: 1.51-8.63, P = 0.025) was significant in the PH36w patients. CONCLUSIONS: The incidence of PH36w was 4.2% and 6.9% in the BPD28d and BPD36w patients, respectively. Oligohydramnios and sepsis were significantly associated with PH36w in VLBWIs.

Management of a Preterm Infant with Renal Tubular Dysgenesis: A Case Report and Review of the Literature.

Renal tubular dysgenesis (RTD) is the absence or poor development of the renal proximal tubules caused by gene mutations in the renin-angiotensin system. Although RTD has been considered fatal, improving neonatal intensive care management has enhanced survival outcomes. However, little has been reported on the survival of extremely preterm infants. This study reports the survival of an extremely preterm infant with RTD and discusses the appropriate management of RTD by reviewing the literature. A female infant weighing 953 g was delivered at 27 weeks' gestation by Cesarean section because of oligohydramnios. She exhibited severe persistent pulmonary hypertension, severe systemic hypotension, and renal dysfunction shortly after birth. Respiratory management was successfully undertaken using nitric oxide inhalation and high-frequency oscillatory ventilation. Desmopressin was effective in maintaining her blood pressure and urinary output. She was diagnosed with RTD based on genetic testing, which revealed a compound heterozygous mutation in the angiotensin-converting enzyme gene in exon 18 (c.2689delC; p.Pro897fs) and exon 20 (c.3095dupT; p.Leu1032fs). At 2 years, she started receiving oral fludrocortisone for treating persistently high serum creatinine levels, which was attributed to nephrogenic diabetes insipidus caused by RTD. Subsequently, her urine output decreased, and renal function was successfully maintained. Currently, there is no established treatment for RTD. Considering cases reported to date, treatment with vasopressin and fludrocortisone appears to be most effective for survival and maintenance of renal function in patients with RTD. This study presents the successful management of RTD using this strategy in an extremely preterm infant.

Maturation of the QT Variability Index is Impaired in Preterm Infants.

Reduced heart rate (HR) variability in preterm infants compared with full-term infants suggests that autonomic cardiac control is developmentally delayed. However, the association between developmental changes in myocardial repolarization and gestational age remains unknown. This study investigated the association between the myocardial repolarization lability index, namely the QT variability index (QTVI) = log10 [(QTv/QTm2)/(HRv/HRm2)], and the perinatal profile of healthy 1-month-old infants. We included 209 infants (143 boys and 87 girls; mean gestational weeks at birth, 38.6 ± 1.7) who were born in university hospitals between 2014 and 2015 without apparent cardiac disease. We compared the ECG variability indices in 28 infants born before 37 gestational weeks (mean gestational weeks at birth, 35.6 ± 1.1 as preterm) and 181 infants born at the average number of gestational weeks (mean gestational weeks at birth, 38.8 ± 1.1 as controls). There was a negative correlation between the QTVI and gestational weeks (r = - 0.460, p = 0.035). QTVI values in preterm infants were larger than those in the controls (0.01 ± 0.50 vs. -0.26 ± 0.48, p = 0.023). In conclusion, the QTVI is negatively correlated with gestational age. The QTVI can serve as an index of the maturity of the cardiac autonomic nervous system and myocardial depolarization.

Complete sequencing and characterization of 21,243 full-length human cDNAs.

As a base for human transcriptome and functional genomics, we created the "full-length long Japan" (FLJ) collection of sequenced human cDNAs. We determined the entire sequence of 21,243 selected clones and found that 14,490 cDNAs (10,897 clusters) were unique to the FLJ collection. About half of them (5,416) seemed to be protein-coding. Of those, 1,999 clusters had not been predicted by computational methods. The distribution of GC content of nonpredicted cDNAs had a peak at approximately 58% compared with a peak at approximately 42%for predicted cDNAs. Thus, there seems to be a slight bias against GC-rich transcripts in current gene prediction procedures. The rest of the cDNAs unique to the FLJ collection (5,481) contained no obvious open reading frames (ORFs) and thus are candidate noncoding RNAs. About one-fourth of them (1,378) showed a clear pattern of splicing. The distribution of GC content of noncoding cDNAs was narrow and had a peak at approximately 42%, relatively low compared with that of protein-coding cDNAs.

Genomic and Transcriptomic Analyses of Bioluminescence Genes in the Enope Squid Watasenia scintillans.

Watasenia scintillans, a sparkling enope squid, has bioluminescence organs to illuminate its body with its own luciferase activity. To clarify the molecular mechanism underlying its scintillation, we analysed high-throughput sequencing data acquired previously and obtained draft genome sequences accomplished with comparative genomic data among the cephalopods. The genome mapped by transcriptome data showed that (1) RNA editing contributed to transcriptome variation of lineage specific genes, such as W. scintillans luciferase, and (2) two types of luciferase enzymes were characterized with reasonable 3D models docked to a luciferin molecule. We report two different types of luciferase in one organism and possibly related to variety of colour types in the W. scintillans fluorescent organs.

Complete genome sequence of the mitochondrial DNA of the sparkling enope squid, Watasenia scintillans.

The sparkling enope squid, Watasenia scintillans, is a deep-sea mollusk inhabiting the western part of the Pacific Ocean. It has the peculiar ability to illuminate its body without the involvement of other organisms. In this study, we extracted the brain DNA from a single squid female caught in the Japan Sea and determined the complete genome sequence of its mitochondrial DNA using the Illumina sequencing platform. The circular sequence is 20,089 bp in length. Using the next-generation sequencing data, we also estimated the mean copy number of mitochondria per cell in the brain to be 108 by comparing the depths of the read data in the nuclear and mitochondrial genomes. The haploid genome size was calculated to be 4.78 Gb. Six heteroplasmy sites were also identified, together with their allele frequencies, in this individual. Our methodology is shown to be useful in mitochondrion-related studies.

Complete genome sequence of the mitochondrial DNA of the river lamprey, Lethenteron japonicum.

Lampreys are eel-like jawless fishes evolutionarily positioned between invertebrates and vertebrates, and have been used as model organisms to explore vertebrate evolution. In this study we determined the complete genome sequence of the mitochondrial DNA of the Japanese river lamprey, Lethenteron japonicum, using next-generation sequencers. The sequence was 16,272 bp in length. The gene content and order were identical to those of the sea lamprey, Petromyzon marinus, which has been the reference among lamprey species. However, the sequence similarity was less than 90%, suggesting the need for the whole-genome sequencing of L. japonicum.

Signal sequence and keyword trap in silico for selection of full-length human cDNAs encoding secretion or membrane proteins from oligo-capped cDNA libraries.

We have developed an in silico method of selection of human full-length cDNAs encoding secretion or membrane proteins from oligo-capped cDNA libraries. Fullness rates were increased to about 80% by combination of the oligo-capping method and ATGpr, software for prediction of translation start point and the coding potential. Then, using 5'-end single-pass sequences, cDNAs having the signal sequence were selected by PSORT ('signal sequence trap'). We also applied 'secretion or membrane protein-related keyword trap' based on the result of BLAST search against the SWISS-PROT database for the cDNAs which could not be selected by PSORT. Using the above procedures, 789 cDNAs were primarily selected and subjected to full-length sequencing, and 334 of these cDNAs were finally selected as novel. Most of the cDNAs (295 cDNAs: 88.3%) were predicted to encode secretion or membrane proteins. In particular, 165(80.5%) of the 205 cDNAs selected by PSORT were predicted to have signal sequences, while 70 (54.2%) of the 129 cDNAs selected by 'keyword trap' preserved the secretion or membrane protein-related keywords. Many important cDNAs were obtained, including transporters, receptors, and ligands, involved in significant cellular functions. Thus, an efficient method of selecting secretion or membrane protein-encoding cDNAs was developed by combining the above four procedures.

Database and analysis system for cDNA clones obtained from full-length enriched cDNA libraries.

We have developed an efficient sequence-analysis system and a database system for clones obtained from full-length enriched cDNA libraries made by using the oligo-capping method. We developed a semi-automatic analysis system for 5'- and 3'-end sequences. It pre-processes raw sequences (vector cut and accurate-sequence region extraction), clusters the sequences, searches for similarities through public databases, annotates completeness of clones and analyzes the ORFs in the sequences. Newly developed or improved programs are used in each step. A new program, ESTiMateFull is used to evaluate and to predict the sequence-fullness based on comparisons with mRNA and EST sequences, respectively. The ATGpr program is used to predict sequence-fullness based on statistical information. The combination of full-length enriched cDNA clones and ATGpr fullness prediction resulted in 70% accuracy in the specificity and the sensitivity of the fullness predictions. For the ORFs predicted by the ATGpr, the signal peptides are predicted and a motif search is performed by our new system. We also developed a program that assembles our sequences with dbEST sequences and developed a system to retrieve clones by the characteristics of the ORFs. As keywords, combination of various results of the analyses can be used for retrieval. And various results such as ORF features and database search results can be shown on the same screen by multiple displays. Full-length clones having interesting functions can thus be retrieved efficiently by using this system.