Association between prepregnancy body mass index or gestational weight gain and adverse pregnancy outcomes among Chinese women with gestational diabetes mellitus: a systematic review and meta-analysis

OBJECTIVE

The association between prepregnancy body mass index (BMI) or gestational weight gain (GWG) and adverse pregnancy outcomes among Chinese women with gestational diabetes mellitus (GDM) is unknown. This study aims to evaluate such association by synthesising the evidence.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed, Web of Science, Scopus, EMBASE, China Biology Medicine disc, China National Knowledge Infrastructure, Wangfang, and China Science and Technology Journal Database searched from inception to 11 August 2023.

ELIGIBILITY CRITERIA

Prospective cohort studies, retrospective cohort studies and case-control studies estimating the relationship of abnormal prepregnancy BMI (including underweight, overweight or obesity) or inappropriate GWG (including excess GWG or insufficient GWG) with adverse pregnancy outcomes of interest were included. Outcomes included macrosomia, caesarean section, preterm birth, gestational hypertension, large for gestational age (LGA) and small for gestational age (SGA).

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently selected studies, extracted the data and assessed the risk of bias. OR estimate and its 95% CI were pooled using Stata software fixed-effect model. Subgroup analysis, meta-regression and sensitivity analysis were performed to ensure credibility of the results.

RESULTS

Twenty-three studies (eighteen retrospective cohort studies, three prospective cohort studies and two case control studies) involving 57 013 Chinese women with GDM were identified. Meta-analysis results showed that compared with GDM women with normal weight, GDM women with underweight were at a higher risk of SGA (OR=1.79 (1.54 to 2.07), five studies involving 31 967 women); women with overweight had higher risks of macrosomia (OR=1.65 (1.49 to 1.82), eleven studies involving 41 683 women), caesarean section (OR=1.48 (1.38 to 1.59), ten studies involving 34 935 women), preterm birth (OR=1.27 (1.13 to 1.43), eight studies involving 38 295 women) and LGA (OR=1.73 (1.54 to 1.95), seven studies involving 31 342 women) and women with obesity had higher risks of macrosomia (OR=2.37 (2.04 to 2.76), eleven studies involving 41 683 women), caesarean section (OR=2.07 (1.84 to 2.32), nine studies involving 34 829 women), preterm birth (OR=1.31 (1.09 to 1.57), eight studies involving 38 295 women) and LGA (OR=2.63 (2.15 to 3.21), six studies involving 31 236 women). Regard to GWG, compared with Chinese GDM women with sufficient GWG, GDM women with excessive GWG had higher risks of macrosomia (OR=1.74 (1.58 to 1.92), twelve studies involving 40 966 women), caesarean section (OR=1.44 (1.36 to 1.53), nine studies involving 36 205 women) and LGA (OR=2.12 (1.96 to 2.29), twelve studies involving 42 342 women); women with insufficient GWG conversely had higher risks of preterm birth (OR=1.59 (1.45 to 1.74), nine studies involving 37 461 women) and SGA (OR=1.38 (1.27 to 1.51), ten studies involving 41 080 women).

CONCLUSIONS

For Chinese women with GDM, abnormal prepregnancy BMI or inappropriate GWG were related to higher risks of many adverse pregnancy outcomes. Therefore, medical staff should pay more attention to the weight management of GDM women during pregnancy.

The exploration of optimal gestational weight gain after oral glucose tolerance test for Chinese women with gestational diabetes mellitus

Now, no recommendations of gestational weight gain (GWG) after gestational diabetes mellitus (GDM) diagnosis for Chinese women was made. This study aimed to explore the optimal GWG after oral glucose tolerance test (OGTT) for Chinese women with GDM. The GWG status of 11,570 women was retrospectively analyzed. Binary regression model and restricted cubic spline were used to estimate the association between GWG after OGTT and the predicted probability of adverse outcomes. Based on above, the optimal GWG was defined as the range that not exceed 1% increase in the predicted probability from the lowest point. Results shown that every increased one unit GWG after OGTT was associated with higher risks of macrosomia, cesarean section and LGA, and lower risk of preterm birth. According to the WHO and Working Group on Obesity in China (WGOC) recommended pre-pregnancy BMI category, the optimal GWG were proposed: 3.66 to 6.66 kg/3.66 to 6.66 kg in underweight group, 3.07 to 6.50 kg/3.02 to 6.40 kg in normal weight group, 1.06 to 2.73 kg/0 to 1.99 kg in overweight group, and not applicable/- 0.22 to 2.53 kg in obese group, respectively. Therefore, it is necessary to classified Chinese population based on the WGOC recommended pre-pregnancy BMI category, that influenced the contribution of pre-pregnancy BMI groups and the optimal GWG recommendation for GDM women with overweight or obesity.

Dietary supplementation of proteases on growth performance, nutrient digestibility, blood characteristics and gut microbiota of growing pigs fed sorghum-based diets

Low-tannin sorghum is an excellent energy source in pig diets. However, sorghum contains several anti-nutritional factors that may have negative effects on nutrient digestibility. The impacts of proteases on growth performance, nutrient digestibility, blood parameters, and gut microbiota of growing pigs fed sorghum-based diets were studied in this study. Ninety-six pigs (20.66 ± 0.65 kg BW) were allocated into three groups (eight pens/group, four pigs/pen): (1) CON (control diet, sorghum-based diet included 66.98% sorghum), (2) PRO1 (CON + 200 mg/kg proteases), (3) PRO2 (CON + 400 mg/kg proteases) for 28 d. No differences were observed in growth performance and apparent total tract digestibility (ATTD) of nutrients between CON and PRO1 groups. Pigs fed PRO2 diet had increased (P < 0.05) BW on d 21 and 28, and increased (P < 0.05) average daily gain during d 14-21 and the overall period compared with pigs fed CON diet. In addition, pigs fed PRO2 diet had improved (P < 0.05) ATTD of gross energy, CP, and DM compared with pigs fed CON and PRO1 diets. Pigs fed PRO2 diet had lower (P < 0.05) plasma globulin (GLB) level and higher (P < 0.05) plasma glucose, albumin (ALB) and immunoglobulin G levels, and ALB/GLB ratio than pigs fed CON and PRO1 diets. Furthermore, pigs fed PRO2 diet had decreased (P < 0.05) the relative abundance of Acidobacteriota at the phylum level and increased (P < 0.05) the relative abundance of Prevotella_9 at the genus level. The linear discriminant analysis effect size analysis also showed that pigs fed PRO2 diet had significantly enriched short-chain fatty acid-producing bacteria, such as Subdoligranulum and Parabacteroides. In conclusion, protease supplementation at 400 mg/kg improved the growth performance of growing pigs fed sorghum-based diets, which may be attributed to the improvement of nutrient digestibility, host metabolism, immune status and associated with the altered gut microbiota profiles.

Application of in vivo brain imaging technology in the basic research of acupuncture-moxibustion for encephalopathy

Acupuncture-moxibustion is remarkably effective on encephalopathy, but its mechanism is unclear. With the continuous development of imaging technology, the in vivo brain imaging technology has been used increasingly in life science research and it also becomes a more effective tool for the basic research of acupuncture-moxibustion in treatment of encephalopathy. The paper summarizes the application of its technology in the basic research of acupuncture-moxibustion for encephalopathy and the characteristics of imaging, as well as the advantages and shortcomings. It is anticipated that the references may be provided for the basic research of acupuncture-moxibustion in treatment of encephalopathy and be conductive to the modernization of acupuncture-moxibustion.

Mediating effects of social support, mental health between stress overload, fatigue and turnover intention among operating theatre nurses

BACKGROUND

The high rate of nurses turnover and nursing staff shortage have been an ongoing concern issue and a challenge for global health systems. To explore the turnover intention among operating theatre nurses, and to test the hypothetical model for estimating the effects of stress overload and fatigue between social support, mental health and turnover intention.

DESIGN

a multi-center and cross-sectional online survey.

METHODS

This study was conducted from October 2020 to March 2021 comprised 1060 operating theatre nurses from 76 Chinese hospitals. The descriptive analysis, independent sample t test and one-way analysis of variance and Spearman correlation analysis were used to explore the relationships among variables by the SPSS software, and stepwise multiple linear regression analysis was utilized to identify influencing factors of turnover intention and its dimensions among operating theatre nurses. A structural equation model was analyzed by the AMOS software.

RESULTS

Social support, mental health, stress overload and fatigue were important predictors of turnover intention among operating theatre nurses. Besides, stress overload positively affected fatigue, mental health and turnover intention; fatigue negatively affected social support, however, fatigue positively affected mental health; social support negatively affected mental health and turnover intention; mental health positively affected turnover intention. Moreover, social support, mental health mediated between stress overload, fatigue and turnover intention among operating theatre nurses.

CONCLUSION

Social support, mental health mediated between stress overload, fatigue and turnover intention among operating theatre nurses.

The effects of plant-based dietary patterns on the risk of developing gestational diabetes mellitus: A systematic review and meta-analysis

BACKGROUND

The worldwide prevention of gestational diabetes mellitus (GDM) is a significant health challenge. Plant-based dietary patterns are a series dietary habits that emphasized foods derived from plant sources more and from animal foods less. Now, no consensus exists on the effects of plant-based dietary patterns on the incident of GDM.

OBJECTIVE

This study aimed to estimate the effects of plant-based dietary patterns on the risk of developing GDM.

METHODS

This systematic review was conducted following the checklist of PRISMA. Six electronic databases including PubMed, Embase, Web of Science, China National Knowledge Infrastructure, Wangfang, and Chinese Scientific Journals Database were searched from inception to November 20, 2022. A fixed or random effect model was used to synthesize results of included studies. Then, subgroup analysis, meta-regression and sensitivity analysis were performed to assure the reliability and stability of the results.

RESULTS

Ten studies including 32,006 participants were identified. The results of this study showed that the better adherence to the plant-based dietary patterns was related to the lower risk of developing GDM (RR = 0.88[0.81 to 0.96], I2 = 14.8%). The slightly stronger association between plant-based diets and the risk of developing GDM was found when healthy plant-based dietary pattern index was included in pooled estimate (RR = 0.86[0.79 to 0.94], I2 = 8.3%), compared with that unhealthy one was included (RR = 0.90[0.82 to 0.98], I2 = 8.3%).

CONCLUSION

The plant-based dietary patterns are associated with a lower risk of developing GDM. Furthermore, healthy plant-based dietary patterns are more recommended than unhealthy one. It is significant to help medical staff to guide pregnant women to choose reasonable diets.

Effect of depressive symptoms on quality of work life in female nurses: a cross-sectional study using propensity score matching

Background

Female nurses have been considered as a vulnerable population in the context of mental health, due to the nature of their work, which can be stressful and emotionally taxing. Understanding the relationship between depressive symptoms and quality of work life (QWL) can contribute to improving mental health and job performance. However, limited studies have focused on the effect of depressive symptoms on QWL in female nurses.

Objectives

The present study aimed to assess the effect of depressive symptoms on female nurses' QWL using propensity score matching (PSM).

Methods

A cross-sectional, online study using convenience sampling was conducted among 1,401 female nurses in China. PSM was used to minimize the impact of potential confounders between no depressive symptoms and depressive symptoms. Stepwise multiple linear regression analyses were performed on the PSM samples to explore the effects of depressive symptoms on the QWL.

Results

The results revealed there were 33.5% of the female nurses reported depressive symptoms before PSM. And female nurses in this study had a moderate level of QWL before PSM (122.11 ± 18.15), which remained steady after PSM (118.33 ± 18.04). After PSM, the final sample contained 864 female nurses. Stepwise multiple linear regression results indicated that depressive symptoms were the most strongly associated with QWL (β = -0.454, p < 0.001).

Conclusion

This study highlights the importance of developing mental health plans and psychological interventions for female nurses to maintain mental health and QWL, which is critical to the nursing workforce's sustainability.

[Airborne fungi monitoring]

Airborne fungi are an important class of aeroallergens that can lead to the development of allergic rhinitis and asthma, and reducing the exposure of fungi is an important strategy to prevent the exacerbation of symptoms in individuals with fungal allergy. Therefore, monitoring airborne fungi and understanding their dispersion patterns are important for clinical diagnosis, treatment and prevention. The purpose of this article is to review the methods of airborne fungi monitoring and factors influencing the distribution and dispersal of airborne fungi.

[Effects of auricular thumbtack needle on lactation function and TDP-43/Btn1A1/XDH pathway in primiparous women with cesarean section]

OBJECTIVE

To observe the effects of auricular thumbtack needle on breast feeding and lactation function in primiparous women with cesarean section, and to explore its mechanism of action from the perspective of lactation-related gene expression.

METHODS

One hundred cases of primiparous women with cesarean section were randomly divided into an observation group (50 cases, 3 cases dropped off) and a control group (50 cases, 2 cases were eliminated). The patients in the control group were treated with routine obstetric care. Based on the treatment of the control group, the patients in the observation group were treated with auricular thumbtack needle at Neifenmi (CO₁₈), Xiong (AH₁₀), Xiongzhui (AH₁₁), Shenmen (TF₄), and Jiaogan (AH_6a), etc., with one side of auricular point selected, only once for a total of 3 d. The lactation initiation time, lactation adequacy rate at postpartum 72 h, exclusive breastfeeding rate at postpartum 42 d, and breastfeeding score after treatment were compared between the two groups. Real-time quantitative PCR and Western blot method were used to detect the mRNA and protein expression levels of TDP-43, Btn1A1 and XDH.

RESULTS

After treatment, the lactation initiation time in the observation group was earlier than that in the control group (P<0.01), and breastfeeding score in the observation group was higher than that in the control group (P<0.01). The lactation adequacy rate at postpartum 72 h was 63.8% (30/47) in the observation group, which was higher than 41.7% (20/48) in the control group (P<0.05). The exclusive breastfeeding rate at postpartum 42 d was 72.3% (34/47) in the observation group, which was higher than 47.9% (23/48) in the control group (P<0.05). The mRNA and protein expression levels of TDP-43 and Btn1A1 in breast milk in the observation group were higher than those in the control group (P<0.01), while there was no statistically significant difference in mRNA and protein expression of XDH in breast milk between the two groups (P>0.05).

CONCLUSION

The auricular thumbtack needle in addition to routine care could promote lactation initiation, improve lactation adequacy rate and exclusive breastfeeding rate in primiparous women with cesarean section, and the action mechanism may be related to up-regulation of TDP-43 and Btn1A1 expression.

Fruit, vegetable, and fruit juice consumption and risk of gestational diabetes mellitus: a systematic review and meta-analysis : List of all authors

BACKGROUND

Fruit, vegetable, and fruit juice intake is associated with the risk of gestational diabetes mellitus (GDM). However, the conclusion is limited and conflicted. The purpose of this systematic review and meta-analysis is to investigate the association between fruit, vegetable, and fruit juice consumption and the risk of GDM.

METHODS

To find relevant studies, we searched PubMed, The Cochrane Library, Web of Science, Embase, ScienceDirect, PsycINFO, CINAHL, Ovid, EBSCO, CBM, CNKI, Wanfang Data, and VIP for the report on prospective cohort studies published from inception to April 8, 2022. Summary relative risks (RR) and 95% confidence intervals (Cis) were estimated using a random-effects model.

RESULTS

A total of 12 studies with 32,794 participants were included in the meta-analysis. Total fruit consumption was associated with a lower risk of GDM (RR = 0.92, 95% CI = 0.86-0.99). Whereas an increasing the consumption of vegetable, including all vegetable (RR = 0.95, 95% CI = 0.87-1.03), starchy vegetable (RR = 1.01, 95% CI = 0.82-1.26), and fruit juice (RR = 0.97, 95% CI = 0.91-1.04) was not associated with a reduction in the risk of GDM. In a dose‒response analysis of eight studies, a 3% reduction in risk of GDM for a 100 g/d increase in fruit consumption (RR = 0.97, 95% CI = 0.96-0.99).

CONCLUSIONS

The findings suggest that higher fruit consumption may reduce the risk of GDM, with a 3% reduction in the risk of GDM for every 100 g/d increase in fruit intake. Higher-quality prospective studies or randomized clinical trials are required to validate the effect of different variations of fruits, vegetables, and fruit juice consumption on the risk of GDM.

Which mothers' breastfeeding behaviours within six weeks postpartum do health workers need to notice? Developing an indicator system based on the Delphi method and analytic hierarchy process

OBJECTIVE

The six weeks postpartum is the high-incidence period of stopping breastfeeding. The clarity of the internal mechanism of behaviour was an effective way to promote breastfeeding. The aim was to reach a consensus on indicators what should be used and prioritised in evaluating mothers' breastfeeding behaviour within six weeks postpartum in order to provide a theoretical reference for health workers to take targeted strategies toward promoting breastfeeding practices.

DESIGN

Two rounds of Delphi method and analytic hierarchy process was conducted in this study. The two-rounds Delphi was performed to select essential indicators and collect revised suggestion. The analytic hierarchy process was adopted for pairwise comparison to rank the significance of primary and secondary indicators.

SETTING AND PARTICIPANTS

The panel included twenty experts with rich breastfeeding information and different general characteristics from China.

FINDINGS

Consensus was achieved to include three primary indicators, seven secondary indicators, and forty-five tertiary indicators in the final indicators system of the mothers' breastfeeding behaviour within six weeks postpartum. The weight sequence of primary indicators was self-regulation behaviour (0.401), at-the-breast feeding behaviour (0.383), and resource utilisation behaviour (0.216). The rank of the secondary indicators was breastfeeding operation skills (0.267), self-decision behaviour (0.144), self-control behaviour (0.130), self-coping behaviour (0.127), breastfeeding self-perception (0.116), resource acquisition behaviour (0.115), and resource coordination behaviour (0.101).

KEY CONCLUSION

The study builds a new and reliable indicators system that intuitively reflects the constituent elements of the mothers' breastfeeding behaviour within six weeks postpartum and provides priorities in primary indicators and secondary indicators.

IMPLICATIONS FOR PRACTICES

The study helps form a clear and scientific cognition on mothers' breastfeeding behaviour within six weeks postpartum and provides a new perspective and intuitive theoretical reference for health workers to take targeted measures to promote breastfeeding practices and achieve substantial public health gains.

Effects of coping on nurses' mental health during the COVID-19 pandemic: Mediating role of social support and psychological resilience

BACKGROUND

Fighting against the COVID-19 pandemic, front-line nurses were under unprecedented psychological pressure. Therefore, it is necessary to promptly evaluate the psychological status of nurses during the COVID-19 epidemic period.

AIM

To investigate nurses' mental health during the COVID-19 pandemic, and to test the mediating role of social support and psychological resilience between coping and mental health.

DESIGN

This was a descriptive, cross-sectional survey which used a structural equation model.

METHOD

In total, 711 registered nurses were included. All participants were invited to complete a socio-demographic questionnaire, the general health questionnaire, the trait coping style questionnaire, the perceived social support scale and the Conner-Davidson Resilience scale.

RESULTS

In total, 50.1% nurses had high risk of mental health. Positive coping positively affected social support and psychological resilience, while it negatively affected mental health. Negative coping negatively affected social support and psychological resilience, while it positively affected mental health. Social support positively affected psychological resilience, while it negatively affected mental health. In addition, social support mediated coping and psychological resilience, and coping and mental health. Moreover, psychological resilience negatively affected mental health, and it mediated coping and mental health.

The mothers' breastfeeding behaviour within six weeks postpartum: new scale development and psychometric validation study

BACKGROUND

The evaluation of mothers' breastfeeding behaviour within 6 weeks postpartum could help health workers comprehensively identify maternal breastfeeding shortcomings, clarify nursing problems, and provide targeted interventions. However, no prior study was found, therefore this study aimed to develop and validate the reliability and validity of the mothers' breastfeeding behaviour scale within 6 weeks postpartum.

METHODS

A main two-step approach was used: (1) a qualitative pilot study using the purposive sampling method was adopted to test the fitness, simplicity, and clarity of items with 30 mothers; (2) a cross-sectional survey using the convenient sampling method was conducted for item analysis and psychometric validation with 600 mothers.

RESULTS

The final version of the scale consisted of 36 items with seven dimensions, explaining 68.852% of the total variance. The Cronbach's α, split-half, and retest coefficients were 0.958, 0.843, and 0.753, respectively. The validity of the scale: (1) Content validity: content validity index (CVI) range of items was between 0.882 and 1.000. The scale-level-CVI was 0.990. (2) Structure validity: The fitting indices were as follows: χ²/ⅆf =2.239, RMR = 0.049, RMSEA = 0.069, TLI = 0.893, CFI = 0.903, IFI = 0.904, PGFI = 0.674, and PNFI = 0.763. (3) Convergent validity: The composite reliability and average variance extracted (AVE) of the seven dimensions were between 0.876 and 0.920 and between 0.594 and 0.696. (4) Distinguish validity: The correlation coefficients were less than the square root of the AVE, except for self-decision behaviour, self-coping behaviour, and self-control behaviour. However, the fit index of the original three-factor model was better than that of the other new models, with significant differences (P < 0.001). (5) Calibration validity: The area under the curve was 0.860 or 0.898 when the scale was used to predict exclusive or any breastfeeding at 42 days. The correlation coefficients of the maternal breasting feeding evaluation scale, breastfeeding self-efficacy short-form scale, and the scale were 0.569 and 0.674, respectively.

CONCLUSION

The newly developed mothers' breastfeeding behaviour scale within 6 weeks postpartum consists of 36 items belonging to seven dimensions with good reliability and validity and is a reliable and valid instrument to be used in future maternal breastfeeding behaviour assessments and interventions.

Mothers' breastfeeding six weeks postpartum and factors influencing exclusive breastfeeding during the first six months

We aimed to assess the feeding pattern and influencing factors within six weeks postpartum on exclusive breastfeeding duration among Chinese mothers. This study was conducted using 2:1 matched case-control study. Cases and controls were matched for maternal age, parity and mode of birth. A total of 210 women were included. Approximately 67.9% of women stopped exclusive breastfeeding within the first six weeks postpartum. Maternal non-exclusive breastfeeding intention, lower maternal educational level, mother-infant skin to skin contact over one hour, unsatisfied breastfeeding self-evaluation and maternal unhealthy condition within the first six weeks were risk factors for ceasing exclusive breastfeeding early.

Mediating effect of resilience between social support and compassion fatigue among intern nursing and midwifery students during COVID-19: a cross-sectional study

AIMS

To examine the mediating effect of resilience between social support and compassion fatigue among intern nursing and midwifery students during COVID-19.

BACKGROUND

Compassion fatigue has become exceedingly common among intern nursing and midwifery students, especially during the COVID-19 pandemic. Social support and resilience can help intern nursing and midwifery students control their negative emotions, reduce compassion fatigue, and increase their well-being. However, the mediating effect of resilience between social support and compassion fatigue remains unclear.

DESIGN

A multicentre cross-sectional survey.

METHODS

A total of 307 intern nursing and midwifery students were recruited from November 2020 to February 2021 in tertiary grade A hospitals in China. Structural equation modelling was applied to analyse the mediating effects of resilience between social support and compassion fatigue. The Social Support Rating Scale, the 10-item Connor-Davidson Resilience Scale, and the Chinese version of the Compassion Fatigue Short Scale were used to collect data. The hypothetical path model was tested by using IBM SPSS version 26.0 and AMOS version 26.0 software.

RESULTS

Intern nursing and midwifery students had moderate compassion fatigue. Social support positively affected resilience (β = 0.514, p < 0.01). Social support negatively affected compassion fatigue (β = - 0.310, p < 0.01), while resilience negatively affected compassion fatigue (β = - 0.283, p < 0.01). Resilience played a mediating role between social support and compassion fatigue.

CONCLUSION

Social support can directly affect the compassion fatigue of intern nursing and midwifery students during COVID-19 and indirectly through resilience. Stronger resilience can reduce compassion fatigue. Accordingly, resilience-based interventions should be developed to reduce compassion fatigue.

Prevalence and risk factors of sub-health and circadian rhythm disorder of cortisol, melatonin, and temperature among Chinese midwives

Objective

This study aimed to explore the influencing factors of sub-health and circadian rhythm disorder among midwives and whether circadian rhythm disorder was associated with sub-health.

Methods

A multi-center cross-sectional study was conducted among 91 Chinese midwives from six hospitals through cluster sampling. Data were collected by demographic questionnaire, Sub-Health Measurement Scale version 1.0, and circadian rhythm detection. Minnesota single and population mean cosine methods were used to analyze the rhythm of cortisol, melatonin, and temperature. Binary logistic regression, nomograph model, and forest plot were performed to identify variables associated with midwives' sub-health.

Results

There were 65 midwives with sub-health and 61, 78, and 48 midwives with non-validation of circadian rhythms of cortisol, melatonin, and temperature among 91 midwives, respectively. Midwives' sub-health was significantly related to age, duration of exercise, weekly working hours, job satisfaction, cortisol rhythm, and melatonin rhythm. Based on these six factors, the nomogram was presented with significant predictive performance for sub-health. Furthermore, cortisol rhythm was significantly associated with physical, mental, and social sub-health, whereas melatonin rhythm was significantly correlated with physical sub-health.

Conclusion

Sub-health and circadian rhythm disorder were generally common among midwives. Nurse administrators are supposed to pay attention and take measures to prevent sub-health and circadian rhythm disorder among midwives.

Changes in the Gut Metabolic Profile of Gestational Diabetes Mellitus Rats Following Probiotic Supplementation

The roles of gut microbiota and metabolomics in women with gestational diabetes mellitus (GDM) are not well understood. This study investigated the gut metabolomic profiling of GDM rats and GDM rats treated with probiotic supplements. Associations between gut metabolites and microbiota were also studied in GDM rats. Liquid chromatography–mass spectrometry was used to detect gut metabolites in GDM rats and GDM rats treated with probiotic supplements of 0.5 g (low-dose group) or 1 g (high-dose group) for 15 days. Each gram of probiotic supplement contained 5 × 107 colony-forming units (CFU) of Lactobacillus rhamnosus LGG and 1 × 108 CFU of Bifidobacterium animalis subspecies lactis Bb12. The association between gut metabolites and microbiota in GDM rats was investigated using Spearman’s correlation. Finally, 10 rats in the normal pregnant group, eight rats in the GDM model group, eight GDM rats in the low-dose probiotics group, and nine GDM rats in the high-dose probiotics group were further studied. Serum parameters and pancreatic and colon histology were significantly changed in GDM rats, and these were restored using probiotic supplements. In total, 999 gut metabolites were detected in the feces, and GDM rats were distinguished from normal rats. The levels of 44 metabolites were increased in GDM rats, and they were alleviated using probiotic supplements. Changes in metabolites in GDM rats were associated with amino acids and bile acids metabolism signaling pathways. Furthermore, changes in metabolites after probiotic supplementation were associated with porphyrin and chlorophyll metabolism pathways. We found that the Allobaculum genus displayed strong positive correlations, whereas the Bryobacter and Gemmatimonas genera displayed strong negative correlations with metabolisms of amino acids and bile acids in GDM rats. The Lactobacillus and Bifidobacterium genera were positively correlated with gut metabolites. Overall, our results showed that metabolism signaling pathways of amino acids and bile acids are associated with the development of GDM. Probiotic supplements alleviate the pathology of GDM through the metabolism pathways of amino acids, bile acids, porphyrin, and chlorophyll.

Prepregnancy body mass index and gestational weight gain are associated with maternal and infant adverse outcomes in Chinese women with gestational diabetes

The gestational weight gain (GWG) range of Chinese women with gestational diabetes mellitus (GDM) remains unclear. Our objective was to identify the ranges of GWG in Chinese women with GDM and to investigate the associations between prepregnancy body mass index (BMI), GWG and maternal-infant adverse outcomes. Cases of GDM women who delivered singletons from 2013 to 2018 in a public hospital were collected. Logistic regression analysis was used to assess the joint effects of prepregnancy BMI and GWG on maternal-infant adverse outcomes. Ultimately, 14,578 women were collected. The ranges of GWG in Chinese women with GDM were different from the National Academy of Medicine's (NAM) recommendation. The ranges of GWG of Chinese women with GDM in the underweight, normal weight, overweight and obese groups were 5.95-21.95 kg, 4.23-21.83 kg, 0.88-21.12 kg and - 1.76 to 19.95 kg, respectively. The risks of large for gestational age (LGA), macrosomia and caesarean delivery were significantly increased with the increasing prepregnancy BMI. Furthermore, the risks of LGA, macrosomia and caesarean delivery were significantly higher in the normal weight group with a GWG higher than the NAM recommendation. Similarly, in the overweight group with a GWG higher than the NAM recommendation, the risks of LGA were significantly higher, while the risks of macrosomia were significantly lower. Overall, we determined the range of GWG in different prepregnancy BMI groups. And GDM women with high prepregnancy BMI and excessive GWG were associated with the higher risks of maternal-infants adverse outcomes in China.

Probiotic supplements alleviate gestational diabetes mellitus by restoring the diversity of gut microbiota: a study based on 16S rRNA sequencing

Probiotics effectively prevent and improve metabolic diseases such as diabetes by regulating the intestinal microenvironment and gut microbiota. However, the effects of probiotics in gestational diabetes mellitus are not clear. Here, we showed that probiotic supplements significantly improved fasting blood glucose in a gestational diabetes mellitus rat model. To further understand the mechanisms of probiotics in gestational diabetes mellitus, the gut microbiota were analyzed via 16S rRNA sequencing. We found that compared with the normal pregnant group, the gestational diabetes mellitus rats had decreased diversity of gut microbiota. Moreover, probiotic supplementation restored the diversity of the gut microbiota in gestational diabetes mellitus rats, and the gut microbiota structure tended to be similar to that of normal pregnant rats. In particular, compared with gestational diabetes mellitus rats, the abundance of Firmicutes and Actinobacteria was higher after probiotic supplementation. Furthermore, activating carbohydrate metabolism and membrane transport pathways may be involved in the potential mechanisms by which probiotic supplements alleviate gestational diabetes mellitus. Overall, our results suggested that probiotic supplementation might be a novel approach to restore the gut microbiota of gestational diabetes mellitus rats and provided an experimental evidence for the use of probiotic supplements to treat gestational diabetes mellitus.

Gestational Diabetes Mellitus and Risk of Delayed Onset of Lactogenesis: A Systematic Review and Meta-Analysis

Background: Gestational diabetes mellitus (GDM) may be associated with delayed onset of lactogenesis (DOL), but it is still inconclusive. Objectives: The study aimed to evaluate the association between GDM and DOL, the prevalence and risk factors of DOL in GDM women. Materials and Methods: A comprehensive search was performed in 10 electronic databases from inception to June 1, 2020. To find more eligible studies, the references of finally eligible studies and relevant reviews were traced manually. A meta-analysis was conducted to calculate the pooled estimates of association, prevalence, and risk factors using random- or fixed-effects models. Results: Eleven eligible articles involving 8,150 women were included in this study. GDM women had a higher risk of DOL (odds ratio [OR] = 1.84, 95% confidence interval [CI] [1.34-2.52]). The prevalence of delayed lactogenesis onset in GDM women was 35.0% (effect size [ES] = 0.35, 95% CI [0.30-0.40]). Primipara (OR = 2.54, 95% CI [1.89-3.42]), advanced age (OR = 1.05, 95% CI [1.03-1.08]), prepregnancy obesity (OR = 1.55, 95% CI [1.19-2.03]), and insulin treatment (OR = 3.07, 95% CI [1.71-5.47]) were risk factors of delayed lactogenesis onset in GDM women. Conclusion: GDM negatively affects the timing of lactogenesis onset. The prevalence of delayed lactogenesis onset in GDM women is 35.0%. Primipara, advanced age, prepregnancy obesity, and insulin treatment are independent risk factors of delayed lactogenesis onset in GDM women.

Factors associated with workplace fatigue among midwives in southern China: A multi-centre cross-sectional study

AIMS

To identify the level of workplace fatigue among midwives and factors influencing their fatigue.

BACKGROUND

Midwives who play an important role in medical care are prone to experience workplace fatigue, which negatively affects their well-being and work quality.

METHODS

A multi-centre cross-sectional study was conducted among 666 Chinese midwives from 38 hospitals in March 2019. Data were collected by four questionnaires of self-designed demographic questions, the Pittsburgh Sleep Quality Index, the Social Support Self-Rating Scale and the 14-item Fatigue Scale. Descriptive statistics, univariate analysis and multiple linear regression were used to analyse the data.

RESULTS

Midwives had moderate levels of fatigue with the mean scores of physical fatigue, mental fatigue and total fatigue being 9.53, 6.25 and 15.79, respectively. Multiple linear regression results showed that sleep quality, social support, job satisfaction, occupational injuries, adverse life events, frequency of irregular meals and employment type were statistically significant factors influencing fatigue among the participants.

CONCLUSIONS

Physical and mental fatigue were generally common among midwives and were affected by personal-related and work-related factors, sleep quality and social support.

IMPLICATIONS FOR NURSING MANAGEMENT

Nurse administrators have the opportunity to advocate for improved health policy under the two children rule to prevent workplace fatigue amongst midwives.

The influence of psychological response and security sense on pregnancy stress during the outbreak of coronavirus disease 2019: A mediating model

AIMS AND OBJECTIVES

To observe the psychological status of pregnant women during COVID-19 pandemic, and to test a hypothetical model that estimates the influence of psychological response to COVID-19 and security sense on pregnancy stress.

BACKGROUND

COVID-19 advanced rapidly and then spread worldwide. Pregnant women were more susceptible to the COVID-19 infection. Furthermore, it is not clear whether this infection will increase the risk of congenital monstrosity, foetal growth restriction, premature delivery or cause other long-term adverse effects.

DESIGN

A descriptive, cross-sectional survey.

METHODS

A total of 331 pregnant women participated in this study. And this research adhered to the STROBE guideline. The psychological questionnaire for emergent events of public health, pregnancy stress scale and security questionnaire were used to collect data. The hypothetical path model was tested using the SPSS version 25.0 software and AMOS version 26.0 software.

RESULTS

Fear and depression were the most common psychological responses among pregnant women during the COVID-19 pandemic. The hypothesis model of this study fitted the data well, and the results showed that psychological response positively affected pregnancy stress, while security sense negatively affected pregnancy stress; security sense mediated between psychological response and pregnancy stress.

CONCLUSION

Nurses and midwives can help reduce the stress in pregnant women by alleviating their psychological response to the COVID-19 pandemic and by improving their security sense.

RELEVANCE TO CLINICAL PRACTICE

It is essential for the health staff to build trust with pregnant women and their families, and communicate accurate information to them. Nurses should promptly conduct a psychological response evaluation and psychological guidance for pregnant women to alleviate their fears and hypochondria related to COVID-19.

A multi-center cross-sectional study on midwives' self-efficacy and influencing factors

AIM

Healthcare professionals who lack self-efficacy may fail to cope with stressful situations, which increases job burnout and turnout. Self-efficacy of midwives with high workload may affect the quality of service. However, little is known about midwives' self-efficacy and related factors. This study aimed to examine the level and influencing factors of self-efficacy among midwives, and to assess the relationships between their self-efficacy and job burnout.

METHODS

This was a multi-center cross-sectional study involving 700 midwives from 33 hospitals in China. Data were collected by three self-administered questionnaires, including a socio-demographic questionnaire, General Self-Efficacy Scale and Maslach Burnout Inventory. Pearson correlation was utilized to analyze the association of self-efficacy with job burnout. A multiple linear regression model was performed to identify variables associated with midwives' self-efficacy.

RESULTS

The score of self-efficacy among Chinese midwives was 24.34 ± 5.28. The incidence of job burnout was 52.9%. The influencing factors of self-efficacy among midwives were low personal accomplishment, emotional exhaustion, length of service, interest in the midwifery field, marital status and whether they came from a one-child family or not.

CONCLUSIONS

Chinese midwives had a moderate level of self-efficacy which easily led to job burnout. Also, several personal-related and work-related factors would affect the self-efficacy of midwives. Nursing managers are called on to attach importance to self-efficacy of midwives and provide effective interventions to improve their self-efficacy.

[Trends analysis of vitamin D status among pregnant women in Hefei during 2015-2017]

From March 2015 to February 2018, 4 728 women aged 18 to 45 years old with single-pregnancy at the gestational age of 13 to 27 weeks in Hefei were recruited to analyze the trend of vitamin D status. The average levels of serum 25(OH)D in 2015, 2016 and 2017 were (43.22±18.41) nmol/L, (39.3±15.1) nmol/L and (36.6±17.0) nmol/L, and the prevalence of vitamin D deficiency were 69.5%, 77.6% and 81.4%, respectively. Compared with 2015, the levels of serum 25(OH)D in pregnant women in 2016 and 2017 decreased by 5.23 (95%CI: 4.10-6.35) nmol/L and 7.98 (95%CI: 6.77-9.19) nmol/L. The OR (95%CI) values for the risk of vitamin D deficiency were 1.88 (95%CI: 1.57-2.24) and 2.41 (95%CI: 1.98-2.93).

[Investigation on depressive mood of Nurses in a Maternal and Child Hospital]

Objective: To understand the depression of nurses in the maternity and child care hospital and in order to provide references for improving the physical and mental health of nurses. Methods: A total of 679 nurses from 14 departments of a provincial maternity and child health care hospital in June 2017 were selected as the subjects to investigate the depression of nurses by questionnaire. Results: The total rate of depression was 40% in this group and the average standard of SDS was (49.45+12.02) , which was higher than the norm in our country and the difference was statistically significant (P<0.01) . The average standard of SDS for nurses in different departments was higher than the norm in our country except the women's health caredepartment. The differences of the depression in age、the age for nurse、monthly income、night shift frequency、children's status、the work feelings and family support were statistically significant (The values of 2 are 12.908、9.953、10.316、19.422、11.246、41.672 and 61.434, P<0.05) . Multivariate Logistics Regression Analysis showed age、family income、night shift frequency、the work feelings、family support were risk factors of depression among nurses, by 26-35 years of age、the monthly income less than 6 000 yuan、night shift frequency (less than 5~6 days) , dislike work、family support for work in general and no support. Conclusion: The rate of depression among nurses in provincial maternity and child health care hospital is high. Hospital departments should attach great importance to the psychological problems of nurses and give psychological intervention in order to improve the mental health level of nurses.

Effect of midwife-led care on birth outcomes of primiparas

BACKGROUND

The high caesarean section rate is a prominent public health problem in China.

AIM

This study aimed to determine the effects of midwife-led care during labour on birth outcomes for healthy primiparas.

DESIGN

Randomized controlled trial.

SETTING

The Obstetrics Department of Fujian Provincial Maternity and Child Health Hospital.

METHODS

A total of 666 primiparas in labour were randomly divided into an intervention and control group (333 in each group). The intervention group received a midwife-led model of care during labour.

RESULTS

Data from 648 cases (331 intervention group and 317 control group) were analysed. The intervention group was less likely to experience caesarean section, postpartum haemorrhage, opiate analgesia, vaginal examinations, neonatal asphyxia, and neonatal hospitalization and was more likely to experience shorter length of labour and vaginal birth than the control group (all, P < 0.05). No differences were found in the number of artificial rupture of membranes and oxytocin use (P > 0.05).

CONCLUSIONS

Midwife-led care can reduce the caesarean section rate, promote normal birth, improve birth outcomes, and promote maternal and child health.

[Combined multiple artery-first approach to pancreatoduodenectomy]

Objective: To investigate the clinical application of combined multiple artery-first approach to pancreatoduodenectomy. Methods: The clinical data of 53 patients who were diagnosed with peripancreatic head tumor at Department of Biliary-Pancreatic Surgery of Second Affiliated Hospital of Harbin Medical University between June 2013 and June 2015 was retrospectively analyzed.Pancreatic enhanced CT scan, magnetic resonance cholangiopancreatography, ultrasonography and tumor marker detection were applied for all the patients preoperatively.The 53 patients were operated by combined multiple artery-first approach(superior+ posterior approach, superior+ inferior approach, posterior+ inferior approach, superior+ posterior+ inferior approach) according to individualized therapeutic concept.And 42 patients underwent pancreatoduodenectomy, 9 patients underwent palliative operation and 2 patients just received exploratory operation. Results: Forty-two peripancreatic head tumor patients underwent pancreatoduodenectomy by applying combined multiple artery-first approach.The median operation time and intraoperative blood loss were (5.4±3.1)hours and (366±297)ml and the harvested lymph node and duration of hospital stay were 19±5 and (14.0±5.6)days.Nine patients underwent "total mesopancreas excision" and the rate of postoperative pancreatic fistula and R0 resection were 38.1% and 88.1%. Anomalous origin hepatic right artery was detected in one patients during the operation and no death occurred within 30 days postoperatively. Conclusion: According to the tumor location and patient's condition, individualistically applying combined multiple artery-first approach can reduce intraoperative blood loss, terminate unnecessary surgery, detect anomalous origin artery, make the tumor resection more radical and pancreatoduodenectomy more safety.

Cloning and transformation of INDUCER of CBF EXPRESSION1 (ICE1) in tomato

The tomato plant (Solanum lycopersicum Mill.) is sensitive to cold, and low field temperatures can result in shortened growth periods and decreased crop yield. Transcription of CRT/DRE-binding factor (CBF) is regulated by INDUCER of CBF EXPRESSION1 (ICE1). CBF activates many downstream genes that confer cold tolerance on plants. ICE1 has been used in genetic engineering to improve cold-resistance in several plant species. Here, ICE1 in a plant expression vector was used to transform a tissue-cultured rhubarb tomato variety using Agrobacterium tumefaciens. The transgenic and control plants were compared at 4°C for 0, 24, and 72 h. We measured leaf physiological indicators related to cold resistance, including malondialdehyde (MDA) and proline (Pro) contents, and peroxidase (POD) and catalase (CAT) activities. At 72 h, the MDA content in transgenic plants was significantly lower than in control plants, indicating a lower membrane lipid injury. The Pro contents and the CAT and POD activities in the transgenic plants increased significantly compared with those of the control plants. For Pro, the increase continued over the prolonged stress exposure, while CAT and POD activities reached peak levels at 24 h. These results are consistent with the roles of Pro, CAT, and POD in defending the integrity of plant cells. Our study not only improves the cold resistance of tomato, but also provides the foundation for further research on the role of ICE1 as a transcription factor in plant cold resistance.

Coupled ferroelectric polarization and magnetization in spinel FeCr2S4

One of the core issues for multiferroicity is the strongly coupled ferroelectric polarization and magnetization, while so far most multiferroics have antiferromagnetic order with nearly zero magnetization. Magnetic spinel compounds with ferrimagnetic order may be alternative candidates offering large magnetization when ferroelectricity can be activated simultaneously. In this work, we investigate the ferroelectricity and magnetism of spinel FeCr₂S₄ in which the Fe²⁺ sublattice and Cr³⁺ sublattice are coupled in antiparallel alignment. Well defined ferroelectric transitions below the Fe²⁺ orbital ordering termperature T_oo = 8.5 K are demonstrated. The ferroelectric polarization has two components. One component arises mainly from the noncollinear conical spin order associated with the spin-orbit coupling, which is thus magnetic field sensitive. The other is probably attributed to the Jahn-Teller distortion induced lattice symmetry breaking, occuring below the orbital ordering of Fe²⁺. Furthermore, the coupled ferroelectric polarization and magnetization in response to magnetic field are observed. The present work suggests that spinel FeCr₂S₄ is a multiferroic offering both ferroelectricity and ferrimagnetism with large net magnetization.

The profile of gene expression and role of nuclear factor kappa B on glomerular injury in rats with Thy-1 nephritis

Mesangioproliferative glomerulonephritis (MsPGN) is a disease of high incidence in humans. Rats with Thy-1 nephritis (Thy-1 N) are used as an animal model for studying MsPGN. Although several studies have demonstrated that many pathological factors could cause the injury of glomerular mesangial cells (GMCs) in Thy-1 N, changes of profile and the molecular mechanism of the disease (i.e. the role of transcription factors) at intervals remain unclear. The purpose of this study was to identify the changes in gene expression profile and to observe the role of nuclear factor kappa B (NF-kappaB) on the pathological change of renal tissue in Thy-1 N rats. Our results showed that the pathological changes of GMCs in Thy-1 N included three phases: apoptosis (40 min), necrosis (24 h) and proliferation (7 days). Concomitantly, at 40 min and on day 7, the up-regulation of 341 genes and 250 genes were observed, while 392 genes and 119 genes were down-regulated in Thy-1 N. Expression of interleukin (IL)-1beta, IL-6, proliferating cell nuclear antigen, alpha-smooth muscle actin, collagen type IV and excretion of urinary protein was increased in rats with Thy-1 N and decreased in pyrrolidine dithiocarbamate-treated rats with Thy-1 N. These data indicated that the significant changes in the gene profile were coupled with the pathological changes of Thy-1 N, and activation of NF-kappaB may contribute to the pathogenesis of GMCs apoptosis, proliferation, extracelluar matrix accumulation and proteinuria in Thy-1 N.

[Experimental investigation on emission characteristic of NOx during micropulverized coal oxidation]

The combustion experiments of HG micronized coal have been conducted by combining DTG and GC-MS. The effects on NOx emission caused by particle size, oxygen concentration and heating rate were analyzed. The results show that under combustion condition that oxygen concentration is 20%, NOx precipitations of HG coal in difference sizes are single-peaked courses. Particle size impacts NOx emission from coal combustion significantly. Micro-pulverized coal reduces NOx emission. Under heating condition with 5 degrees C/min, 10 degrees C/min and 20 degrees C/min, precipitation of NO and NO2 is increased with heating rate rising, and temperature parallelized with maximum NO precipitation rate is increased with heating rate rising as well. With increasing of oxygen concentration in combustion, NOx precipitation increases correspondingly, and temperature parallelized with maximum NOx precipitation rate is reduced.

Body-centered-cubic Ni and its magnetic properties

The body-centered-cubic (bcc) phase of Ni, which does not exist in nature, has been achieved as a thin film on GaAs(001) at 170 K via molecular beam epitaxy. The bcc Ni is ferromagnetic with a Curie temperature of 456 K and possesses a magnetic moment of 0.52+/-0.08 micro(B)/atom. The cubic magnetocrystalline anisotropy of bcc Ni is determined to be +4.0x10(5) ergs x cm(-3), as opposed to -5.7x10(4) ergs x cm(-3) for the naturally occurring face-centered-cubic (fcc) Ni. This sharp contrast in the magnetic anisotropy is attributed to the different electronic band structures between bcc Ni and fcc Ni, which are determined using angle-resolved photoemission with synchrotron radiation.

Photoinduced quantum interference antiresonances in pi-conjugated polymers

We observed photoinduced quantum interference antiresonances between several discrete infrared-active vibrations and the lower-polaron continuous absorption band in a series of pi-conjugated polymer films having superior planar orders, where the polaron transition energy is relatively small. The photoinduced Fano-type antiresonances are well explained by extending the amplitude mode model beyond the adiabatic limit. The agreement between the data and the model confirms the presence of a continuous electronic band above the polaron state. We show that high frequency modes are strongly coupled to electrons, with implications for superconductivity.

Conjugation-length dependence of spin-dependent exciton formation rates in pi-conjugated oligomers and polymers

We have measured the ratio, r = sigma(S)/sigma(T) of the formation cross section, sigma of singlet and triplet excitons from polarons in pi-conjugated oligomer and polymer films, using a spectroscopic technique we developed recently. We discovered a universal relation between r and the conjugation length (CL): r(-1) depends linearly on CL-1, irrespective of the chain structure. Since r is directly related to the maximum possible electroluminescence quantum efficiency in organic light emitting diodes (OLED), our results indicate that polymers have an advantage over small molecules in OLED applications.

Mechanism of transfer of NO from extracellular S-nitrosothiols into the cytosol by cell-surface protein disulfide isomerase

N-dansylhomocysteine (DnsHCys) is quenched on S-nitrosation. The product of this reaction, N-dansyl-S-nitrosohomocysteine, is a sensitive, direct fluorogenic substrate for the denitrosation activity of protein disulfide isomerase (PDI) with an apparent K(M) of 2 microM. S-nitroso-BSA (BSA-NO) competitively inhibited this reaction with an apparent K(I) of 1 microM. The oxidized form of DnsHCys, N,N-didansylhomocystine, rapidly accumulated in cells and was reduced to DnsHCys. The fluorescence of DnsHCys-preloaded human umbilical endothelial cells and hamster lung fibroblasts were monitored as a function of extracellular BSA-NO concentration via dynamic fluorescence microscopy. The observed quenching of the DnsHCys fluorescence was an indirect measure of cell surface PDI (csPDI) catalyzed denitrosation of extracellular S-nitrosothiols as decrease or increase in the csPDI levels in HT1080 fibrosarcoma cells correlated with the rate of quenching and the PDI inhibitors, 5,5'-dithio-bis-3-nitrobenzoate and 4-(N-(S-glutathionylacetyl) amino)phenylarsenoxide inhibited quenching. The apparent K(M) values for denitrosation of BSA-NO by csPDI ranged from 12 microM to 30 microM. Depletion of membrane N(2)O(3) with the lipophylic antioxidant, vitamin E, inhibited csPDI-mediated quenching rates of DnsHCys fluorescence by approximately 70%. The K(M) for BSA-NO increased by approximately 3-fold and V(max) decreased by approximately 4-fold. These findings suggest that csPDI catalyzed NO released from extracellular S-nitrosothiols accumulates in the membrane where it reacts with O2 to produce N(2)O(3). Intracellular thiols may then be nitrosated by N2O3 at the membrane-cytosol interface.

Efficacy trial of Vi polysaccharide vaccine against typhoid fever in south-western China

OBJECTIVE

To test the efficacy of locally produced Vi vaccine over a time period of longer than one year.

METHODS

A double-blinded, randomized field trial was performed in Guangxi Zhuang Autonomous Region in south-western China, using 30 micrograms doses of locally produced Vi. Enrolled subjects were 3-50 years of age, although the majority (92%) were school-aged children, who have the highest rate of typhoid fever in this setting. A total of 131,271 people were systematically allocated a single dose of 30 micrograms of Vi polysaccharide or saline placebo. The study population was followed for 19 months, with passive surveillance conducted in the Ministry of Health and the Regional Health and Anti-epidemic Centre (HAEC). Clinically suspected cases of typhoid fever were confirmed by blood culture, or by serological reaction with O-antigen (Widal tests).

FINDINGS

After 19 months, there were 23 culture-confirmed cases of typhoid fever in the placebo group versus 7 cases in the Vi group (Protective efficacy (PE) = 69%; 95% CI = 28%, 87%). Most of the isolates were from school-aged children: 22 cases in the placebo group versus 6 in the Vi group (PE = 72%; 95% CI = 32%, 82%). No serious post-injection reactions were observed. The locally produced Vi polysaccharide vaccine showed levels of protective efficacy similar to those for Vi vaccine produced in industrial countries.

CONCLUSION

The slightly higher dose of vaccine did not seem to alter efficacy significantly in China.

Phosphoglycerate kinase acts in tumour angiogenesis as a disulphide reductase

Disulphide bonds in secreted proteins are considered to be inert because of the oxidizing nature of the extracellular milieu. An exception to this rule is a reductase secreted by tumour cells that reduces disulphide bonds in the serine proteinase plasmin. Reduction of plasmin initiates proteolytic cleavage in the kringle 5 domain and release of the tumour blood vessel inhibitor angiostatin. New blood vessel formation or angiogenesis is critical for tumour expansion and metastasis. Here we show that the plasmin reductase isolated from conditioned medium of fibrosarcoma cells is the glycolytic enzyme phosphoglycerate kinase. Recombinant phosphoglycerate kinase had the same specific activity as the fibrosarcoma-derived protein. Plasma of mice bearing fibrosarcoma tumours contained several-fold more phosphoglycerate kinase, as compared with mice without tumours. Administration of phosphoglycerate kinase to tumour-bearing mice caused an increase in plasma levels of angiostatin, and a decrease in tumour vascularity and rate of tumour growth. Our findings indicate that phosphoglycerate kinase not only functions in glycolysis but is secreted by tumour cells and participates in the angiogenic process as a disulphide reductase.

Presence of closely spaced protein thiols on the surface of mammalian cells

It has been proposed that certain cell-surface proteins undergo redox reactions, that is, transfer of hydrogens and electrons between closely spaced cysteine thiols that can lead to reduction, formation, or interchange of disulfide bonds. This concept was tested using a membrane-impermeable trivalent arsenical to identify closely spaced thiols in cell-surface proteins. We attached the trivalent arsenical, phenylarsenoxide, to the thiol of reduced glutathione to produce 4-(N-(S-glutathionylacetyl)amino)phenylarsenoxide (GSAO). GSAO bound tightly to synthetic, peptide, and protein dithiols like thioredoxin, but not to monothiols. To identify cell-surface proteins that contain closely spaced thiols, we attached a biotin moiety through a spacer arm to the primary amino group of the gamma-glutamyl residue of GSAO (GSAO-B). Incorporation of GSAO-B into proteins was assessed by measuring the biotin using streptavidin-peroxidase. Up to 12 distinct proteins were labeled with GSAO-B on the surface of endothelial and fibrosarcoma cells. The pattern of labeled proteins differed between the different cell types. Protein disulfide isomerase was one of the proteins on the endothelial and fibrosarcoma cell surface that incorporated GSAO-B. These findings demonstrate that the cell-surface environment can support the existence of closely spaced protein thiols and suggest that at least some of these thiols are redox active.

The neuropeptides VIP and PACAP inhibit IL-2 transcription by decreasing c-Jun and increasing JunB expression in T cells

Vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP) act as macrophage and T-cell deactivators. Previously we established that VIP/PACAP limit T-cell activation directly, by inhibiting interleukin 2 (IL-2), and indirectly, by reducing the macrophage costimulatory functions. The nature of the IL-2 transcriptional factors affected by VIP/PACAP has not been elucidated. Here we investigate the effect of VIP on the AP-l complexes bound to several regulatory sites. VIP/PACAP downregulate c-Jun, and upregulate JunB mRNA and protein. The reduction in c-Jun correlates with the inhibition of the c-Jun N-terminal kinase (JNK). The effects of VIP/PACAP on c-Jun and JunB expression lead to changes in the composition of the AP-l complexes, from c-Jun/Fos to JunB/Fos dimers, with a subsequent decrease in DNA binding and loss of transactivating activity.

Two-dimensional electronic excitations in self-assembled conjugated polymer nanocrystals

Several spectroscopic methods were applied to study the characteristic properties of the electronic excitations in thin films of regioregular and regiorandom polythiophene polymers. In the regioregular polymers, which form two-dimensional lamellar structures, increased interchain coupling strongly influences the traditional one-dimensional electronic properties of the polymer chains. The photogenerated charge excitations (polarons) show two-dimensional delocalization that results in a relatively small polaronic energy, multiple absorption bands in the gap where the lowest energy band becomes dominant, and associated infrared active vibrations with reverse absorption bands caused by electron-vibration interferences. The relatively weak absorption bands of the delocalized polaron in the visible and near-infrared spectral ranges may help to achieve laser action in nanocrystalline polymer devices using current injection.

[Determination of chiral purity of synthetic amino acids by high performance liquid chromatography]

A series of synthetic beta-heterocyclic and beta-naphthyl alanine and aromatic substituted phenylalanine were separated by reversed-phase HPLC as diastereomeric derivatives obtained after derivatization with (1-fluoro-2,4-dinitrophenyl)-5-L-valinamide (FDNP-Val-NH2). The separation was performed with gradient elution. The mobile phase A was acetonitrile containing 0.1% trifluoroacetic acid and mobile phase B was 0.1% trifluoroacetic acid. According to the hydrophobicity of the side chain of the amino acids, 6 different linear gradient programs were selected and all gradients completed in 20 minutes. Good resolution was obtained for neutral amino acids. All L-L diastereomer of neutral amino acids (the first letter refers to the configuration of amino acid) were eluted faster than the D-L diastereomer with retention times less than 16 minutes. In the same gradient eluting system, the hydrophobic parameter (pi value) and the position of the substituent in benzene ring of phenylalanine also influence the retention time of diastereomers. Usually the retention time of the phenylalanine with a large pi value was longer than that with a small one. Among the three phenylalanines containing the same substituent, compounds with the substituent in 2-postion gave the shortest retention time. In the case of basic amino acids, the D-L diastereomers eluted prior to the L-L diastereomers and showed rather poor resolution. The chiral purity (ee) of the optical active amino acids (synthetic DL-amino acids after resolution by different enzymes) were calculated with the equation as follows: ee = [[A(L- or D-) - A(D- or L-)]/[A(L-) + A(D-)]] x 100% (L- or D-), A: peak area; L-, D-: amino acid diastereomer.

Redox control of exofacial protein thiols/disulfides by protein disulfide isomerase

Protein disulfide isomerase (PDI) facilitates proper folding and disulfide bonding of nascent proteins in the endoplasmic reticulum and is secreted by cells and associates with the cell surface. We examined the consequence of over- or underexpression of PDI in HT1080 fibrosarcoma cells for the redox state of cell-surface protein thiols/disulfides. Overexpression of PDI resulted in 3.6-4. 2-fold enhanced secretion of PDI and 1.5-1.7-fold increase in surface-bound PDI. Antisense-mediated underexpression of PDI caused 38-53% decreased secretion and 10-33% decrease in surface-bound PDI. Using 5,5'-dithio-bis(2-nitrobenzoic acid) to measure surface protein thiols, a 41-50% increase in surface thiols was observed in PDI-overexpressing cells, whereas a 29-33% decrease was observed in underexpressing cells. Surface thiol content was strongly correlated with cellular (r = 0.998) and secreted (r = 0.969) PDI levels. The pattern of exofacial protein thiols was examined by labeling with the membrane-impermeable thiol reactive compound, 3-(N-maleimidylpropionyl)biocytin. Fourteen identifiable proteins on HT1080 cells were labeled with 3-(N-maleimidylpropionyl)biocytin. The intensity of labeling of 11 proteins was increased with overexpression of PDI, whereas the intensity of labeling of 3 of the 11 proteins was clearly decreased with underexpression of PDI. These findings indicated that secreted PDI was controlling the redox state of existing exofacial protein thiols or reactive disulfide bonds.

Dynamics of environmental supplementation of iodine: four years' experience of iodination of irrigation water in Hotien, Xinjiang, China

Hotien prefecture, Xinjiang Province, China, in the Taklamakan Desert, is an area of severe iodine deficiency. Because usual methods of iodine supplementation failed here, we began supplementation in 1992 with potassium iodate, which was added to irrigation water (Lancet 1994; 334:107-110). We report 4 y experience with this method in 3 townships that contained a total treated population of 37,000. Potassium iodate was dripped into irrigation water (to a concentration 10-80 microg/l) during a 2- to 4-wk period. During the 3 y that followed, no further supplementation was made, and iodine concentrations increased several fold in crops and plants, sheep and chicken thyroid glands, and meat and in urine of children 2-6 y of age and of women who were of childbearing age. Infant mortality decreased 50%, and sheep production increased 43%. Iodine repletion of soil through irrigation water is an effective and cost-efficient way of providing iodine in appropriate situations.

Effect on infant mortality of iodination of irrigation water in a severely iodine-deficient area of China

BACKGROUND

Hotien county in Xinjiang province, China, is an area of severe iodine deficiency and has a high infantmortality rate. We investigated whether iodine replacement through iodination of the irrigation water would decrease infant mortality.

METHODS

We added potassium iodate to irrigation water over a 2 to 4 week period beginning in 1992 in certain areas of three townships (Tusala, Long Ru, and Bakechi). Logistic regression analysis was used to compare the odds ratios for infant and neonatal mortality in treated and intreated areas.

FINDINGS

The median urinary iodine concentration significantly increased in women of child-bearing age from < 10 micrograms/L to 55 micrograms/L. Infant-mortality rates decreased in the treated areas of Long Ru (mean [SD] 58.2 [4.4] per 1000 births to 28.7 [7.1] per 1000 births), Tusala (47.4 [12.4] per 1000 births to 19.1 [1.5] per 1000 births), and Bakechi (106.2 [9.5] per 1000 births to 57.3 [7.3] per 1000 births). Similar results were also seen for neonatal mortality. On regression analysis iodine treatment and time were significant independent predictors of infant mortality.

INTERPRETATION

Iodine supplementation of irrigation water in areas of severe iodine deficiency decreases neonatal and infant mortality. Iodine replacement has probably been an important factor in the national decrease in infant mortality in China.

Fc gamma RIIA H/R 131 polymorphism, subclass-specific IgG anti-heparin/platelet factor 4 antibodies and clinical course in patients with heparin-induced thrombocytopenia and thrombosis

The explanation why only a subset of patients with heparin-induced thrombocytopenia (HIT) develop clinically apparent thromboses (HITT) remains uncertain. It has been proposed that platelet activation induced by cross-linking of Fc gamma RIIA by anti-heparin/platelet factor 4 (PF4) antibodies is central to the pathogenesis of thrombosis. The observation that a common functional polymorphism of Fc gamma RIIA, involving either an arginine (R) or histidine (H) at amino acid 131, may underlie disease susceptibility prompted us to investigate the prevalence of receptor isoforms in patients with HIT and HITT. Furthermore, because these isoforms reportedly differ in their avidity for immune complexes containing human IgG2, we also analyzed sera from patients with HIT and HITT for the prevalence of various subclass-specific IgG anti-heparin/PF4 antibodies. No difference in the allele frequency of Fc gamma RIIA-H131 or R131 was identified among 13 patients with HIT or 23 with HITT compared with 102 controls (chi 2 = 1.21, P = .8). Furthermore, although most patients had IgG2 antibodies (62%), IgG, was the predominant subclass in 30 of the 34 patients with IgG anti-heparin/PF4 antibodies and in 12 was the exclusive subclass found. Also, there was no association between the concordance of IgG2 anti-heparin/ PF4 antibodies and the expression of Fc gamma RIIA-H131 in patients with HITT compared with patients with thrombocytopenia alone. These results make it unlikely that the Fc gamma RIIA-H131 isoform or IgG2 anti-heparin/PF4 antibodies are required to develop HITT, suggesting that factors in addition to cross-linking of Fc gamma RIIA receptors contribute to the pathogenesis of thrombosis in patients with heparin-dependent antiplatelet: antibodies.

Rapid detection of the Fc gamma RIIA-H/R 131 ligand-binding polymorphism using an allele-specific restriction enzyme digestion (ASRED)

A polymorphism of the gene for Fc gamma RIIA, arginine (R) or histidine (H) at position 131, alters the ability of the receptor to bind certain IgG subclasses. Identification of the Fc gamma RIIA-H/R 131 genotype has assumed increasing importance in disorders of host defense, immunohematologic diseases and systemic autoimmune disorders. We report a new method for determination of this genotype in which an allele-specific restriction enzyme site is introduced into an Fc gamma RIIA PCR product from genomic DNA, and polymorphism assignment is determined by restriction enzyme digestion followed by agarose gel electrophoresis. This method is more rapid, more reliable and less expensive than currently available methods.