Identification and functional characterization of conserved cis-regulatory elements responsible for early fruit development in cucurbit crops.

A number of cis-regulatory elements (CREs) conserved during evolution have been found to be responsible for phenotypic novelty and variation. Cucurbit crops such as cucumber (Cucumis sativus), watermelon (Citrullus lanatus), melon (Cucumis melo), and squash (Cucurbita maxima) develop fruits from an inferior ovary and share some similar biological processes during fruit development. Whether conserved regulatory sequences play critical roles in fruit development of cucurbit crops remains to be explored. In six well-studied cucurbit species, we identified 392,438 conserved noncoding sequences (CNSs), including 82,756 that are specific to cucurbits, by comparative genomics. Genome-wide profiling of accessible chromatin regions (ACRs) and gene expression patterns mapped 20,865 to 43,204 ACRs and their potential target genes for two fruit tissues at two key developmental stages in six cucurbits. Integrated analysis of CNSs and ACRs revealed 4,431 syntenic orthologous CNSs, including 1,687 cucurbit-specific CNSs that overlap with ACRs that are present in all six cucurbit crops and that may regulate the expression of 757 adjacent orthologous genes. CRISPR mutations targeting two CNSs present in the 1,687 cucurbit-specific sequences resulted in substantially altered fruit shape and gene expression patterns of adjacent NAC1 (NAM, ATAF1/2, and CUC2) and EXT-like (EXTENSIN-like) genes, validating the regulatory roles of these CNSs in fruit development. These results not only provide a number of target CREs for cucurbit crop improvement, but also provide insight into the roles of CREs in plant biology and during evolution.

Structure and function analyses of the SRC gene in Pacific white shrimp Litopenaeus vannamei.

SRC gene encodes scavenger receptor class C, a member of the scavenger receptor family, and has only been identified and investigated in invertebrates. Our previous studies have revealed that SRC is a novel candidate gene associated with body weight in Pacific white shrimp (Litopenaeus vannamei). In order to comprehend the underlying mechanism by which LvSRC affects shrimp growth, we analyzed the structure, phylogeny, expression profiles and RNA interference (RNAi) of this gene in L. vannamei. We found that LvSRC contains two CCP domains and one MAM domain, with the highest expression level in the heart and relatively low expression level in other tissues. Notably, LvSRC exhibited significantly higher expression levels in the fast-growing group among groups with different growth rates, suggesting its potential involvement as a gene contributing to the growth of L. vannamei. RNAi of LvSRC inhibited body length and body weight gain compared to the control groups. Moreover, through RNA-seq analysis, we identified 598 differentially expressed genes (DEGs), including genes associated with growth, immunity, protein processing and modification, signal transduction, lipid synthesis and metabolism. Furthermore, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses revealed significant changes in the signaling pathways related to growth, lipid metabolism and immune response, suggesting that LvSRC exhibits the potential to participate in diverse physiological processes and immune regulation. These findings deepen our understanding of the structure and function of the SRC in shrimp and lay the foundation for further research into the regulatory mechanism of LvSRC. Additionally, they provide potential applications in shrimp genetics and breeding.

Sparse deconvolution for background noise suppression with total variation regularization in light field microscopy.

In this Letter, we present a method aiming at background noise removal in the 3D reconstruction of light field microscopy (LFM). Sparsity and Hessian regularization are taken as two prior knowledges to process the original light field image before 3D deconvolution. Due to the noise suppression function of total variation (TV) regularization, we add the TV regularization term to the 3D Richardson-Lucy (RL) deconvolution. By comparing the light field reconstruction results of our method with another state-of-the-art method that is also based on RL deconvolution, the proposed method shows improved performance in terms of removing background noise and detail enhancement. This method will be beneficial to the application of LFM in biological high-quality imaging.

Gene Structure, Expression and Function Analysis of MEF2 in the Pacific White Shrimp Litopenaeus vannamei.

The Pacific white shrimp Litopenaeus vannamei is the most economically important crustacean in the world. The growth and development of shrimp muscle has always been the focus of attention. Myocyte Enhancer Factor 2 (MEF2), a member of MADS transcription factor, has an essential influence on various growth and development programs, including myogenesis. In this study, based on the genome and transcriptome data of L. vannamei, the gene structure and expression profiles of MEF2 were characterized. We found that the LvMEF2 was widely expressed in various tissues, mainly in the Oka organ, brain, intestine, heart, and muscle. Moreover, LvMEF2 has a large number of splice variants, and the main forms are the mutually exclusive exon and alternative 5' splice site. The expression profiles of the LvMEF2 splice variants varied under different conditions. Interestingly, some splice variants have tissue or developmental expression specificity. After RNA interference into LvMEF2, the increment in the body length and weight decreased significantly and even caused death, suggesting that LvMEF2 can affect the growth and survival of L. vannamei. Transcriptome analysis showed that after LvMEF2 was knocked down, the protein synthesis and immune-related pathways were affected, and the associated muscle protein synthesis decreased, indicating that LvMEF2 affected muscle formation and the immune system. The results provide an important basis for future studies of the MEF2 gene and the mechanism of muscle growth and development in shrimp.

Is intravenous immunoglobulin a risk factor for necrotizing enterocolitis in neonates with haemolytic disease of the newborn? A retrospective cohort study.

BACKGROUND AND OBJECTIVES: To assess whether the use of intravenous immunoglobulin (IVIG) in late-preterm and term newborns with haemolytic disease of the newborn (HDN) is associated with an increased risk of necrotizing enterocolitis (NEC). MATERIALS AND METHODS: A retrospective cohort study was conducted in a tertiary centre. Infants with HDN during early neonatal period (<7 days) who were of ≥34 weeks' gestation and born between January 2019 and October 2021 were included. Propensity score, interaction as well as univariate and multiple logistic regression analyses were employed. RESULTS: One-thousand two-hundred and fifty-nine infants with HDN were enrolled, of whom 192 (15.3%) received IVIG. NEC was diagnosed in 29 (2.3%) patients with 5 (2.6%) in the IVIG group and 24 (2.2%) in the non-IVIG group. No significant association between IVIG administration and confirmed NEC was observed using univariate analysis (p > 0.05). The possible predictors of NEC, as assessed by multivariate analysis, were caesarean delivery, haemoglobin on admission <130 g/L and patent ductus arteriosus (PDA). There was no interactive effect of IVIG against NEC for prematurity, low birth weight, caesarean delivery, haemoglobin on admission <130 g/L and PDA. CONCLUSIONS: In late-preterm and term infants with HDN, there was no evidence that the early use of IVIG led to the development of NEC.

A very preterm infant born to mother of mirror syndrome secondary to fetomaternal hemorrhage: a case report.

BACKGROUND: Mirror syndrome (MS) is defined as maternal edema with fetal hydrops and placental edema with different etiologies, such as rhesus isoimmunization and twin-twin transfusion syndrome. Herein, we showcased a unique MS case secondary to fetomaternal hemorrhage (FMH). CASE PRESENTATION: A 32-year-old gravida 2 para 0 woman diagnosed with fetal hydrops was admitted to our hospital. Maternal laboratory tests revealed anemia, slightly increased creatinine and uric acid levels, hypoproteinemia, and significantly increased alpha-fetoprotein and hemoglobin-F levels. Therefore, FMH was diagnosed initially. Two days after admission, the woman had unexpectedly progressive anasarca and started to feel chest distress, palpitations, lethargy, and oliguria, and MS was suspected. An emergency cesarean section was performed to terminate the pregnancy. The maternal clinical symptoms and laboratory tests rapidly improved after delivery. A very preterm infant with a 2080-g birthweight at 31 weeks gestation survived after emergency cesarean section, active resuscitation, emergency blood transfusion, abdominocentesis, and advanced life support. CONCLUSIONS: FMH could develop into MS, providing new insights into the etiology of MS. Once MS is diagnosed, emergency cesarean section might be an alternative treatment. The very preterm infant survived with a favorable long-term outcome, and a well-trained perinatal work team is needed for such cases.

The Effects of Suprasegmental Phonological Training on English Reading Comprehension: Evidence from Chinese EFL Learners.

This study aims to investigate the effect of suprasegmental phonological training on connected-text reading comprehension of Chinese university students with different English reading proficiency levels. A sample of 160 freshmen was recruited and randomly divided into experimental and control groups, and the experimental group was given a 12-week training on stress, intonation and rhythm in English. Comparison and analysis of the subjects' reading comprehension performance, involving overall accuracy and speed as well as literal and inferential comprehension, reveal that: (1) suprasegmental phonological training exerts positive effects on the subjects' overall reading comprehension, especially on reading time and literal comprehension; (2) lower-proficiency readers improve more remarkably than higher-proficiency readers in terms of overall accuracy and literal comprehension, while the effect of the training on reading time is significant regardless of the subjects' reading proficiency. The results indicate that with explicit instruction and intensive exposure to suprasegmental knowledge, students' automaticity in lower level processing, such as parsing and understanding propositional messages, can be increased. From a perspective of interaction among different cognitive and psychological processes of reading comprehension, this study can shed light on developing students' reading comprehension in EFL contexts.

[Risk factors for endotracheal intubation during resuscitation in the delivery room among very preterm infants].

OBJECTIVE: To explore the risk factors for endotracheal intubation during resuscitation in the delivery room among very preterm infants. METHODS: A retrospective analysis was performed for 455 very preterm infants who were admitted to the neonatal intensive care unit from January 2017 to December 2019. They were divided into an intubation group (n=79) and a non-intubation group (n=376) according to whether endotracheal intubation was performed during resuscitation. The risk factors for endotracheal intubation during resuscitation were evaluated by multivariate logistic regression analysis. RESULTS: The intubation rate was 17.4% (79/455). Compared with the intubation group, the non-intubation group had significantly higher gestational age, birth weight, and rates of caesarean birth, delayed cord clamping (DCC), resuscitation quality improvement, regular use of antenatal glucocorticoids in mothers and premature rupture of membranes > 18 hours (P < 0.05), but significantly lower rates of maternal gestational diabetes mellitus, placental abruption, placenta previa or placenta previa status, and maternal thyroid dysfunction (P < 0.05). Regular use of antenatal glucocorticoids in mothers (OR=0.368, P < 0.05) and DCC (OR=0.222, P < 0.05) were protective factors against intubation during resuscitation, while younger gestational age, birth weight < 750 g, maternal gestational diabetes mellitus, and placenta previa or placenta previa status were risk factors for intubation during resuscitation (P < 0.05). CONCLUSIONS: Very preterm infants with younger gestational age, birth weight < 750 g, maternal diabetes mellitus, placenta previa or placenta previa status may have a higher risk for endotracheal intubation after birth. The regular use of antenatal glucocorticoids and DCC can reduce the risk of intubation during resuscitation in very preterm infants.

[Risk factors for metabolic bone disease of prematurity in very/extremely low birth weight infants: a multicenter investigation in China].

OBJECTIVE: To investigate the incidence rate and risk factors for metabolic bone disease of prematurity (MBDP) in very low birth weight/extremely low birth weight (VLBW/ELBW) infants. METHODS: The medical data of 61 786 neonates from multiple centers of China between September 1, 2013 and August 31, 2016 were retrospectively investigated, including 504 VLBW/ELBW preterm infants who met the inclusion criteria. Among the 504 infants, 108 infants diagnosed with MBDP were enrolled as the MBDP group and the remaining 396 infants were enrolled as the non-MBDP group. The two groups were compared in terms of general information of mothers and preterm infants, major diseases during hospitalization, nutritional support strategies, and other treatment conditions. The multivariate logistic regression analysis was used to investigate the risk factors for MBDP. RESULTS: The incidence rate of MBDP was 19.4% (88/452) in VLBW preterm infants and 38.5% (20/52) in ELBW preterm infants. The incidence rate of MBDP was 21.7% in preterm infants with a gestational age of < 32 weeks and 45.5% in those with a gestational age of < 28 weeks. The univariate analysis showed that compared with the non-MBDP group, the MBDP group had significantly lower gestational age and birth weight, a significantly longer length of hospital stay, and a significantly higher incidence rate of extrauterine growth retardation (P < 0.05). Compared with the non-MBDP group, the MBDP group had significantly higher incidence rates of neonatal sepsis, anemia, hypocalcemia, and retinopathy of prematurity (P < 0.05). The MBDP group had a significantly lower mean feeding speed, a significantly higher age when reaching total enteral feeding, and a significantly longer duration of parenteral nutrition (P < 0.05). The use rate of caffeine citrate in the MBDP group was significantly higher, but the use rate of erythropoietin was significantly lower than that in the non-MBDP group (P < 0.05). The multivariate logistic regression analysis showed that gestational age < 32 weeks, hypocalcemia, extrauterine growth retardation at discharge, and neonatal sepsis were risk factors for MBDP (P < 0.05). CONCLUSIONS: A lower gestational age, hypocalcemia, extrauterine growth retardation at discharge, and neonatal sepsis may be associated an increased risk of MBDP in VLBW/ELBW preterm infants. It is necessary to strengthen perinatal healthcare, avoid premature delivery, improve the awareness of the prevention and treatment of MBDP among neonatal pediatricians, and adopt positive and reasonable nutrition strategies and comprehensive management measures for preterm infants.

[Application of metabolomics in neonatal clinical practice].

Metabolomics is an emerging and popular subject in the post-genome era, and a large number of studies have been noted on the application of metabolomics in health evaluation, growth and development evaluation, disease diagnosis, and therapeutic efficacy evaluation. As a special period of life, the neonatal period is characterized by rapid cell renewing, consumption of a lot of energy and materials, and changes in metabolic pathways, all of which affect the level of metabolites. However, there is still no reference standard for metabolic level and profile in neonates. This article reviews the current status of metabolic research on neonatal growth and development and common diseases and related clinical application of metabolomics, so as to provide new ideas for nutrition guidance and evaluation, selection of therapeutic regimens, and new drug research in neonates.

T1 polymorphism in a disintegrin and metalloproteinase 33 (ADAM33) gene may contribute to the risk of childhood asthma in Asians.

OBJECTIVE: Polymorphisms in ADAM33 gene have been implicated in susceptibility to the risk of childhood asthma. However, the results remain controversial. We performed meta-analyses to clarify the relationship between them. METHODS: Relevant articles were searched in PubMed, Embase, Wanfang, and China National Knowledge Infrastructure. The Odds ratio (OR) with 95% confidence interval (CI) was used to assess the strength of the associations. RESULTS: Fourteen studies with five ADAM33 polymorphisms (F + 1, T1, T2, S2, and V4) were identified, involving 2687 cases and 2996 controls. ADAM33 F + 1, T2, and T1 polymorphisms showed significant associations with asthma risks in the overall and Caucasian children, Asian children, and Caucasian and Chinese children, respectively; however, these significant results were unstable in sensitivity analysis. T1 revealed significant and stable associations with asthma risks among Asian children in the dominant (OR = 2.00, 95% CI = 1.40-2.87, P = 0.0002) and codominant (OR = 3.06, 95% CI = 1.71-5.50, P = 0.0002) models; in cumulative meta-analyses, these significant results were robust. Concerning S2 or V4 polymorphism, no significant associations were observed. CONCLUSION: These findings demonstrate that ADAM33 T1 polymorphism might be a potential susceptible predictor of asthma for Asian children. Further functional studies between this polymorphism and asthma risks are warranted.

[Prospective and controlled study on effect of fortified human milk feeding on infants with extremely and very low birth weight during hospital stay].

OBJECTIVE: To explore the effect of fortified human milk feeding on growth and complications of infants with extremely and very low birth weight (ELBW/VLBW) during hospital stay by a prospective, random and controlled study. METHODS: In the study, 122 ELBW/VLBW infants were enrolled and divided into two groups. The infants fed with human breast milk, combined with human milk fortification (HMF) during hospital stay were named HMF group (n=62), and those fed exclusively with premature formula were named premature formula feeding group (PF group, n=60). The data of the infants'growth (the velocity of increase on the weight, length, head circumference and upper arm circumference), the time of rebounding to birth weight, the time of needing intravenous nutrition, the time of hospitalizing, the proportion of extrauterine growth retardation (EUGR) during hospital stay, the level of hemoglobin, bone metabolism and incidence of complications were compared between the two groups. RESULTS: Among the 122 infants included, (1) the length increment in HMF group was higher than PF group [(0.89 ± 0.23) cm/week vs. (0.79 ± 0.34) cm/week, P=0.04]; there were no significant differences in the weight gain, head circumference increment and upper arm circumference increment (P>0.05); (2) the age of rebounding to birth weight [(10.13 ± 4.03) d vs. (8.03 ± 3.28) d, P=0.002] and the duration of intravenous nutrition [(16.77 ± 6.63) d vs. (14.23 ± 4.15) d, P=0.01] in HMF group were longer than that in PF group, there were no significant differences between the two groups in the hospital stay and age achieved feeding; (3) there were no significant differences between the two groups in the incidence rate of EUGR during hospital stay (P>0.05); (4) the level of calcium at birth in HMF group was lower than that in PF group [(2.19 ± 0.22) mmol/L vs.( 2.32 ± 0.27) mmol/L, P=0.005], and the level of alkaline phosphatase (AKP) in HMF group at discharge was higher than in PF group [(363.98 ± 122.49) mmol/L vs. (299.73 ± 117.39) mmol/L, P=0.004]; (5) the incidence of the feeding intolerance (6.5% vs. 18.3%, P=0.04) and sepsis (4.8% vs. 16.7%, P=0.03) in HMF group were less than in PF group, there were no significant differences between the two groups on the morbidity of necrotizing enterocditis, retinopathy of prematurity (ROP), and bronchopulmonary dysplasia (BPD) (P>0.05). CONCLUSION: HMF for premature infants may ensure the same growth pattern as those fed by premature formula, promote the calcium absorption, decrease the incidence of sepsis and feeding intolerance, and does not increase the incidence of necrotizing enterocolitis.

Gene structure, expression and function analysis of the MyoD gene in the Pacific white shrimp Litopenaeus vannamei.

The Pacific white shrimp Litopenaeus vannamei is a representative species of decapod crustacean and an economically important marine aquaculture species worldwide. However, research on the genes involved in muscle growth and development in shrimp is still lacking. MyoD is recognized as a crucial regulator of myogenesis and plays an essential role in muscle growth and differentiation in various animals. Nonetheless, little information is available concerning the function of this gene among crustaceans. In this study, we identified a sequence of the MyoD gene (LvMyoD) with a conserved bHLH domain in the L. vannamei genome. Phylogenetic analysis revealed that both the overall protein sequence and specific functional sites of LvMyoD are highly conserved with those of other crustacean species and that they are evolutionarily closely related to vertebrate MyoD and Myf5. LvMyoD expression is initially high during early muscle development in shrimp and gradually decreases after 40 days post-larval development. In adults, the muscle-specific expression of LvMyoD was confirmed through RT-qPCR analysis. Knockdown of LvMyoD inhibited the growth of the shrimp in body length and weight. Histological observation and transcriptome sequencing of muscle samples after RNA interference (RNAi) revealed nuclear agglutination and looseness in muscle fibers. Additionally, we observed significant effects on the expression of genes involved in heat shock proteins, myosins, actins, protein synthesis, and glucose metabolism. These findings suggest that LvMyoD plays a critical role in regulating muscle protein synthesis and muscle cell differentiation. Overall, this study highlights the involvement of LvMyoD in myogenesis and muscle growth, suggesting that it is a potentially important regulatory target for shrimp breeding efforts.

Effects of family integrated care on weight gain in extremely preterm infants.

BACKGROUND: Family integrated care (FICare) is a model that integrates families as partners in the modern neonatal intensive care unit (NICU) care and which can improve the health outcomes of preterm infants. Our study aimed to explore the effect of FICare on extremely preterm infants. METHODS: Overall, 182 preterm infants with complete data were collected from June 2017 to June 2018 in the Chongqing Health Center for Women and Children. Sixty-six of 182 infants were enrolled into the FICare group, and another 66 matched subjects were in the control group. SPSS v. 20.0 software (SPSS Inc., Chicago, IL, USA) was used for statistical analysis. The correlation between each factor and weight gain was analyzed by linear regression. RESULTS: The rate of weight gain during hospitalization (t=4.32), oxygen exposure time (Z=1.967), hospitalization expenses (t=3.03) and the incidence of retinopathy of prematurity (ROP) (χ2=4.805) were higher in the FICare group (P<0.05). Elevated birth weight was associated with a decrease of the weight growth rate (P<0.001). The growth rate of small-for-gestational-age (SGA) infants was higher than normal gestational age infants, P=0.011. Every one year of increase in maternal age (P=0.016), each additional day for restoration days of birth weight (P=0.023), and each increment of δZ score (P<0.001) increased the weight growth rate. The irregular use of hormones reduced the weight growth rate (P=0.023). Compared with the control group, the weight growth rate of FICare group increased (P<0.001). CONCLUSIONS: FICare can significantly improve the weight gain in preterm infants ≤32 weeks during hospitalization.

Interfering with Rac1-activation during neonatal monocyte-macrophage differentiation influences the inflammatory responses of M1 macrophages.

Necrotizing enterocolitis (NEC) is a life-threatening, inflammatory disease affecting premature infants with intestinal necrosis, but the mechanism remains unclear. Neonatal macrophages are thought to play an important role in the pathogenesis of NEC through the production of proinflammatory cytokines. Restriction of cytokine expression in macrophages of NEC tissues may be beneficial. In adult macrophages, interfering with Rac1 has been shown to influence the expression of cytokines. Here, we investigated whether interfering with Rac1 in neonatal macrophages affects their inflammatory responses. First, we found that Rac1-activation was upregulated in the macrophages of rats with NEC model induction compared to controls. The M1 macrophages derived from human neonatal monocytes showed greater Rac1-activation than the M2 macrophages derived from the same monocytes. Inhibition of Rac1-activation by NSC23766 potently reduced the production of proinflammatory cytokines in these M1 macrophages. While neonatal monocytes differentiated into M1 macrophages in vitro, NSC23766 significantly altered cell function during the first six days of incubation with GM-CSF rather than during the subsequent stimulation phase. However, the same effect of NSC23766 was not observed in adult macrophages. Using mass spectrometry, Y-box binding protein 1 (YB1) was identified as being downregulated upon inhibition of Rac1-activation in the neonatal macrophages. Moreover, we found that inhibition of Rac1-activation shortens the poly A tail of PABPC1 mRNA, thereby reducing the translation of PABPC1 mRNA. Consequently, the downregulation of PABPC1 resulted in a reduced translation of YB1 mRNA. Furthermore, we found that TLR4 expression was downregulated in neonatal macrophages, while YB1 expression was reduced. Adding resatorvid (TLR4 signaling inhibitor) to the macrophages treated with NSC23766 did not further reduce the cytokine expression. These findings reveal a novel Rac1-mediated pathway to inhibit cytokine expression in neonatal M1 macrophages and suggest potential targets for the prevention or treatment of NEC.

Comparing two different placental transfusion strategies for very preterm infants at birth: a matched-pairs study.

OBJECTIVE: To evaluate the clinical outcomes of using the extra-uterine placental transfusion (EPT) approach in very preterm infants (VPIs, gestational age <32 weeks) and compare this to delayed cord clamping (DCC) after birth. METHODS: In this matched pairs study, we compared the clinical outcomes of the EPT group to those of the DCC group. EPT were performed in fifty-three VPIs, of whom 27 were singletons and 25 were twins. The singleton VPIs were matched for gestational age (±5 days) and delivery mode, and the twin VPIs were matched between each other with the first twin subjected to DCC and the second twin to EPT. Data on the infants were collected and analysed as an overall group. A twin subgroup consisting of DCC and EPT groups was also analysed separately. The primary study outcome was either death or major morbidities. RESULTS: In total, 100 infants were included (n = 50 EPT group, n = 50 DCC group). The gestational ages of the DCC and EPT groups were (29.16 ± 1.76) and (29.12 ± 1.84) weeks, respectively. There were no differences in either deaths or major morbidities and other clinical outcomes, including the resuscitation variables, haemoglobin levels and red blood cell transfusion, between the two groups. In twin subgroups (gestational age 29.05 ± 1.89 weeks), EPT was associated with a higher rate of necrotizing enterocolitis (NEC) when compared with DCC (odds ratio = 7 (95% CI, 1.06 to 56.89), p = 0.031). CONCLUSIONS: In twin subgroups, the incidence of NEC was higher in the EPT group when compared to the DCC group and therefore based on an abundance of caution the use of EPT in very preterm twins is not recommended.

Extra-uterine placental transfusion (EPT) is an alternative new form of placental transfusion. It can alleviate the problem of delayed respiratory support during DCC. It can also be performed in some placental abruption cases.EPT may lead to the same clinical outcome as DCC in singleton pregnancies but based on an abundance of caution it is not recommended for very preterm twins.

Structure and function analyses of the Mmd2 gene in pacific white shrimp Litopenaeus vannamei.

Monocyte to macrophage differentiation factor 2 gene (Mmd2) encodes a member of the progestin and adipoQ receptor (PAQR) family, and plays a key role in growth and development. Our previous studies had found Mmd2 (Monocyte to macrophage differentiation factor 2) is a new candidate gene for growth traits in Pacific white shrimp (Litopenaeus vannamei). For the purpose of understanding the underlying mechanism of LvMmd2 affecting the growth of shrimp, we analyzed the gene structure, phylogeny, expression profiles and RNA interference of this gene in L. vannamei. We found the LvMmd2 gene sequence was highly conserved in transmembrane regions, it was widely expressed in different tissues, with the highest expression level in the eye stalk. Knockdown LvMmd2 could significantly promote body length and body weight gain, suggesting it is a growth suppressor. Through transcriptome analysis we identified 422 differentially expressed genes (DEGs) between the dsMmd2 group and control group, among which 337 genes were upregulated in the dsMmd2 group, including numerous muscle-related genes and protein synthesis genes. Further bioinformatics analysis showed that growth, metabolism, and immune-related signal pathway had changed significantly. The above results greatly increase our understanding on the conservative structure and function of LvMmd2 gene, and provide potential application prospects in genetics and breeding.

Phototherapy: a new risk factor for necrotizing enterocolitis in very low birth weight preterm infants? a retrospective case-control study.

OBJECTIVE: To investigate the association between phototherapy (PT) and the development of necrotizing enterocolitis (NEC) in very low birth weight (VLBW) infants. STUDY DESIGN: A retrospective case-control study was conducted on VLBW infants with or without NEC (stage IIA or greater) born at ≤35 weeks' gestation in a tertiary hospital over 7 years. Sample size calculation, trend test, as well as univariate and multiple logistic regression analyses were employed. RESULTS: A total of 824 VLBW infants were reviewed, with 74 cases and 122 controls finally enrolled. The odds of NEC increased with the duration and number of PT sessions. Exposure to >120 h and >4 instances of PT were significantly associated with NEC in multivariate analysis. CONCLUSION: This is the first study suggesting a potential association between PT and development of NEC in VLBW infants. This association needs further exploration.

Delayed versus immediate cord clamping in dichorionic twins <32 weeks: a retrospective study.

OBJECTIVES: Strong evidence imply that delayed cord clamping (DCC) provides significant benefits for singleton neonates. However, there is little information about the safety or efficacy of DCC in twins to recommend for or against DCC in twins in guidelines. We aimed to determine the effect of DCC on dichorionic twins born at <32 weeks of gestation. STUDY DESIGN: This is a retrospective cohort study comparing the neonatal and maternal outcomes of immediate cord clamping (ICC) [<15 second (s)] versus DCC (at 60 s). Generalized estimating equations models were performed accounting for twin correlation. RESULTS: A total of 82 pairs of twins (DCC: 41; ICC: 41) were included in analysis. The primary outcome of death before discharge occurred in 3.66% of twins in the DCC group and 7.32% in the ICC group, without a significant difference between the groups. Compared to ICC group, DCC was associated with increased hemoglobin levels [ß1 coefficient 6.51; 95% confidence interval (CI) 0.69-12.32. ß2 coefficient 5.80; 95% CI 0.07-11.54] at 12-24 h of life. There were no significant differences between the groups in neonatal death, neonatal major morbidities and maternal bleeding complications, although DCC was associated with higher estimated maternal blood loss in the cesarean section group (p = .005). CONCLUSIONS: DCC for 60 s in dichorionic twins born at <32 weeks of gestation was associated with increased neonatal hemoglobin levels, when compared with ICC. The finding of a higher estimated maternal blood loss by cesarean section in the DCC group calls for further trials to assess maternal safety of this procedure in this patient population.