Delivery room resuscitation and short-term outcomes of extremely preterm and extremely low birth weight infants: a multicenter survey in North China.

BACKGROUND: Delivery room resuscitation assists preterm infants, especially extremely preterm infants (EPI) and extremely low birth weight infants (ELBWI), in breathing support, while it potentially exerts a negative impact on the lungs and outcomes of preterm infants. This study aimed to assess delivery room resuscitation and discharge outcomes of EPI and ELBWI in China. METHODS: The clinical data of EPI (gestational age [GA] <28 weeks) and ELBWI (birth weight [BW] <1000 g), admitted within 72 h of birth in 33 neonatal intensive care units from five provinces and cities in North China between 2017 and 2018, were analyzed. The primary outcomes were delivery room resuscitation and risk factors for delivery room intubation (DRI). The secondary outcomes were survival rates, incidence of bronchopulmonary dysplasia (BPD), and risk factors for BPD. RESULTS: A cohort of 952 preterm infants were enrolled. The incidence of DRI, chest compressions, and administration of epinephrine was 55.9% (532/952), 12.5% (119/952), and 7.0% (67/952), respectively. Multivariate analysis revealed that the risk factors for DRI were GA <28 weeks (odds ratio [OR], 3.147; 95% confidence interval [CI], 2.082-4.755), BW <1000 g (OR, 2.240; 95% CI, 1.606-3.125), and antepartum infection (OR, 1.429; 95% CI, 1.044-1.956). The survival rate was 65.9% (627/952) and was dependent on GA. The rate of BPD was 29.3% (181/627). Multivariate analysis showed that the risk factors for BPD were male (OR, 1.603; 95% CI, 1.061-2.424), DRI (OR, 2.094; 95% CI, 1.328-3.303), respiratory distress syndrome exposed to ≥2 doses of pulmonary surfactants (PS; OR, 2.700; 95% CI, 1.679-4.343), and mechanical ventilation ≥7 days (OR, 4.358; 95% CI, 2.777-6.837). However, a larger BW (OR, 0.998; 95% CI, 0.996-0.999), antenatal steroid (OR, 0.577; 95% CI, 0.379-0.880), and PS use in the delivery room (OR, 0.273; 95% CI, 0.160-0.467) were preventive factors for BPD (all P < 0.05). CONCLUSION: Improving delivery room resuscitation and management of respiratory complications are imperative during early management of the health of EPI and ELBWI.

Lexical tone and stuttering loci in Mandarin: evidence from preschool children who stutter.

The purpose of this study was to examine the relationship between stuttering loci and lexical tone in Mandarin-speaking preschoolers. Conversational samples from 20 Taiwanese children who stutter (CWS; M = 4:9; range = 3:2-6:4) were analysed for frequency and type of speech disfluency and lexical tone associated with stuttering-like disfluencies (SLDs). Results indicated that SLDs were significantly more likely to be produced on Mandarin syllables carrying Tone 3 and Tone 4 syllables compared to syllables carrying either Tone 1 or Tone 2. Post-hoc analyses revealed: (1) no significant differences in the stuttering frequencies between Tone 1 and Tone 2, or between Tone 3 and Tone 4, and (2) a higher incidence of stuttering on syllables carrying Tone 3 and Tone 4 embedded in conflicting (as opposed to compatible) tonal contexts. Results suggest that the higher incidence of stuttering on Mandarin syllables carrying either Tone 3 or 4 may be attributed to the increased level of speech motor demand underlying rapid F0 change both within and across syllables.

Neohydatothrips (Thysanoptera: Thripidae) from China: new species and records, with a key to species.

Three new species of Neohydatothrips (Thripidae: Sericothripinae) are described and illustrated from China: N. concavus sp. n., N. flavicingulus sp. n. and N. luteolipes sp. n.; and two species previously recorded from Taiwan are here reported for mainland China for the first time: N. plynopygus (Karny) and N. tabulifer (Priesner). A key to the 16 Neohydatothrips species recorded from China (including Taiwan) is provided.

One new species, four new records and key to species of Hydatothrips (Thysanoptera: Thripidae) from China (including Taiwan).

Hydatothrips ormosiae sp. n. (Thripidae: Sericothripinae) is described from southern China; H. ekasi, H. liquidambara and H. onari Kudô are newly recorded for mainland China, and H. noro Kudô is newly recorded for Taiwan. A key to the 16 Hydatothrips species recorded from China (including Taiwan) is provided.

Depletion of Bhmt elevates sonic hedgehog transcript level and increases ß-cell number in zebrafish.

Betaine homocysteine S-methyltransferase (BHMT, EC 2.1.1.5) is a key enzyme in the methionine cycle and is highly expressed in the liver. Despite its important biochemical function, it is not known whether BHMT plays a role during organ development. In this report, we showed that early in development of zebrafish before endoderm organogenesis, bhmt is first expressed in the yolk syncytial layer and then after liver formation becomes a liver-enriched gene. By using the anti-bhmt morpholinos that deplete the Bhmt, we found that in morphant embryos, several endoderm-derived organs, including liver, exocrine pancreas, and intestine are hypoplastic. Strikingly, the number of ß-cells in the pancreatic islet was increased rather than reduced in the morphant. Additional studies showed that Bhmt depletion elevates the sonic hedgehog (shh) transcript level in the morphant, whereas Bhmt-depletion in the Shh-deficient mutant syu failed to rescue the isletless phenotype. These molecular and genetic data strongly suggest that Shh functions downstream of Bhmt to promote ß-cell development. Therefore, although there are still many intriguing questions to be answered, our finding may identify a novel function for Bhmt involving modulation of Shh signaling to control ß-cell development.

Overexpression of TAPETUM DETERMINANT1 alters the cell fates in the Arabidopsis carpel and tapetum via genetic interaction with excess microsporocytes1/extra sporogenous cells.

Previously, we reported that the TAPETUM DETERMINANT1 (TPD1) gene is required for specialization of tapetal cells in the Arabidopsis (Arabidopsis thaliana) anther. The tpd1 mutant is phenotypically identical to the excess microsporocytes1 (ems1)/extra sporogenous cells (exs) mutant. The TPD1 and EMS1/EXS genes may function in the same developmental pathway in the Arabidopsis anther. Here, we further report that overexpression of TPD1 alters the cell fates in the Arabidopsis carpel and tapetum. When TPD1 was expressed ectopically in the wild-type Arabidopsis carpel, the number of cells in the carpel increased significantly, showing that the ectopic expression of TPD1 protein could activate the cell division in the carpel. Furthermore, the genetic analysis showed that the activation of cell division in the transgenic carpel by TPD1 was dependent on EMS1/EXS, as it did not happen in the ems1/exs mutant. This result further suggests that TPD1 regulates cell fates in coordination with EMS1/EXS. Moreover, overexpression of TPD1 in tapetal cells also delayed the degeneration of tapetum. The TPD1 may function not only in the specialization of tapetal cells but also in the maintenance of tapetal cell fate.

VANGUARD1 encodes a pectin methylesterase that enhances pollen tube growth in the Arabidopsis style and transmitting tract.

In flowering plants, penetration of the pollen tube through stigma, style, and transmitting tract is essential for delivery of sperm nuclei to the egg cells embedded deeply within female tissues. Despite its importance in plant reproduction, little is known about the underlying molecular mechanisms that regulate the navigation of the pollen tube through the stigma, style, and transmitting tract. Here, we report the identification and characterization of an Arabidopsis thaliana gene, VANGUARD1 (VGD1) that encodes a pectin methylesterase (PME)-homologous protein of 595 amino acids and is required for enhancing the growth of pollen tubes in the style and transmitting tract tissues. VGD1 was expressed specifically in pollen grain and the pollen tube. The VGD1 protein was distributed throughout the pollen grain and pollen tube, including the plasma membrane and cell wall. Functional interruption of VGD1 reduced PME activity in the pollen to 82% of the wild type and greatly retarded the growth of the pollen tube in the style and transmitting tract, resulting in a significant reduction of male fertility. In addition, the vgd1 pollen tubes were unstable and burst more frequently when germinated and grown on in vitro culture medium, compared with wild-type pollen tubes. Our study suggests that the VGD1 product is required for growth of the pollen tube, possibly via modifying the cell wall and enhancing the interaction of the pollen tube with the female style and transmitting tract tissues.

Tapetum determinant1 is required for cell specialization in the Arabidopsis anther.

In flowering plants, pollen formation depends on the differentiation and interaction of two cell types in the anther: the reproductive cells, called microsporocytes, and somatic cells that form the tapetum. The microsporocytes generate microspores, whereas the tapetal cells support the development of microspores into mature pollen grains. Despite their importance to plant reproduction, little is known about the underlying genetic mechanisms that regulate the differentiation and interaction of these highly specialized cells in the anther. Here, we report the identification and characterization of a novel tapetum determinant1 (TPD1) gene that is required for the specialization of tapetal cells in the Arabidopsis anther. Analysis of the male-sterile mutant, tpd1, showed that functional interruption of TPD1 caused the precursors of tapetal cells to differentiate and develop into microsporocytes instead of tapetum. As a results, extra microsporocytes were formed and tapetum was absent in developing tpd1 anthers. Molecular cloning of TPD1 revealed that it encodes a small protein of 176 amino acids. In addition, tpd1 was phenotypically similar to excess microsporocytes1/extra sporogenous cells (ems1/exs) single and tpd1 ems1/exs double mutants. These data suggest that the TPD1 product plays an important role in the differentiation of tapetal cells, possibly in coordination with the EMS1/EXS gene product, a Leu-rich repeat receptor protein kinase.