[A pre-conception cohort study of fertility and its related factors among couples with the intention of conception].

Objective: To describe fertility and explore factors associated with it among pre-conception couples of childbearing age. Methods: Based on the pre-conceptional offspring trajectory study of the School of Public Health of Fudan University, couples of childbearing age who participated in the pre-conception physical examination in Shanghai Jiading District from 2016 to 2021 were recruited and followed up. Couples' time to pregnancy (TTP) was analyzed and Cox proportional hazards regression model was used to explore the factors associated with TTP. Kaplan-Meier was used to calculate each menstrual cycle's cumulative pregnancy rate. Results: A total of 1 095 preconception couples were included in the analysis, the M(Q1,Q3)of TTP was 4.33 (2.41, 9.78) menstrual cycles. Age of women (FR=0.90, 95%CI: 0.85-0.95, P<0.001), women who were overweight or obese before pregnancy (FR=0.36, 95%CI: 0.24-0.55, P<0.001), women who were exposed to second-hand smoking (FR=0.63, 95%CI: 0.44-0.92, P=0.016), women whose home or office had been renovated in the past 2 years and had a particular smell (FR=0.46, 95%CI: 0.26-0.81, P=0.008) were risk factors for impaired fertility. Regular menstrual cycles (FR=1.64, 95%CI: 1.16-2.31, P=0.005), females who often drank tea/coffee (FR=1.55, 95%CI: 1.11-2.17, P=0.011) and males who took folic acid before conception (FR=2.35, 95%CI: 1.38-4.23, P=0.002) were associated with better fertility. The cumulative pregnancy rate of 3, 6, and 12 menstrual cycles was 37.6%, 64.4%, and 78.4%, respectively. Conclusion: Older couples, overweight or obesity before pregnancy, irregular menstruation, exposure to secondhand smoke and decoration pollutants in females are associated with impaired fertility. Frequent tea/coffee drinking before pregnancy in females and taking folic acid before pregnancy in males are associated with shortened conception time.

Effects of conjugated linoleic acid on the expression levels of miR-27 and miR-143 in pig adipose tissue.

In this study, we evaluated the effect and possible mech-anism of action of dietary conjugated linoleic acid (CLA) on pig body fat deposition. Landrace piglets (N = 48) were randomly divided into three groups, which were fed diets containing 0% (control), 1%, or 2% CLA. Dorsal and abdominal subcutaneous adipose tissues were col-lected, and real-time polymerase chain reaction (PCR) was used to de-termine the expression of adipocyte differentiation marker genes and associated microRNAs (miRNAs). Our results indicated that dietary CLA significantly decreased body fat deposition in the pig dorsum. The expression of adipocyte differentiation marker genes, including peroxi-some proliferator-activated receptor (PPAR)-γ and CCAAT/enhancer-binding protein α (C/EBPα) were not affected, whereas the expression of fatty acid binding protein 4 (FABP4) was significantly enhanced (P < 0.05). The expression of miR-27 and miR-143 in adipose tissue was significantly decreased. Data analysis indicated a significant negative correlation between miR-27 and FABP4 expression in the dorsal sub-cutaneous adipose tissue. In addition, the expression of miR-143 and miR-27 exhibited a significant negative relationship with FABP4 and PPARγ in the abdominal subcutaneous adipose tissue. Thus, miRNA levels in adipose tissues could be modulated by CLA, thereby affecting adipose metabolism.

Improvement in the carcass traits and meat quality of growing-finishing Rongchang pigs by conjugated linoleic acid through altered gene expression of muscle fiber types.

A total of 160 Rongchang pigs (26.76±1.78 kg) were randomly assigned to 5 dietary treatment groups until their body weight (BW) reached 90 kg. The diets were supplemented with 0, 0.5, 1.0, 1.5, and 2.0% conjugated linoleic acid (CLA). Our results showed that the 1.0 to 2.0% CLA-fed pigs had less back fat deposition when their BW reached 90 kg than the pigs that received less than 1% CLA. During the 30 to 60 kg growing period, 1.0, 1.5, and 2.0% CLA treatments improved pork quality by significantly reducing the pork pH (P<0.01) and color value (P<0.05), but they increased marble scaling (P<0.01). Similarly, the 1.5 and 2.0% CLA-fed pigs had more marble than other pigs when their BW reached 90 kg. Furthermore, CLA significantly affected the expression of muscle fiber-type genes. The 1.5% CLA-fed pigs exhibited the highest mRNA expression of MyHC1 and MyHC2a (P<0.05) at 60 kg BW. At 90 kg BW, the highest expression of MyHC1 and MyHC2a (P<0.05) was found in the 2.0% CLA group. However, MyHC2x was downregulated in the CLA-fed pigs at this time. In addition, CLA supplements did not evidently alter mRNA expression of MyHC2b at all times. These results demonstrate that CLA could affect carcass traits and improve the meat quality of growing-finishing pigs by altering the expression of genes related to muscle growth and development; 1-1.5% CLA was the most appropriate CLA dose.

First Report of Sclerotinia Rot of Chinese Atractylodes Caused by Sclerotinia nivalis in China.

Chinese atractylodes (Atractylodes japonica Koidz.ez Kitam.) is a perennial herb in the Compositae family, and is widely distributed in China. The dried rhizomes of the plant are used in traditional Chinese medicine. During the summer of 2011, typical signs and symptoms of Sclerotinia rot were observed on Chinese atractylodes in a production field of Liaoning Province of China. Symptoms were observed in plants at the flowering stage, distributed in patches throughout the rows, and with a disease incidence of approximately 10 to 15%. The lower mature leaves of infected plants first became yellow and wilted, basal stem areas showed a black-brown rot at the same time under conditions of high humidity, and white cottony mycelium formed along the basal stem and soil surfaces. Ultimately, the basal stem and roots rotted and the plants wilted and died quickly. Black, irregular sclerotia (average 0.8 to 6.9 mm in diameter) were also observed within the pith cavity of split stems and rotted roots. The pathogen was isolated from symptomatic tissues and sclerotia, surface disinfested with 2% sodium hypochlorite, and cultured on potato dextrose agar (PDA) (1). The fungus was mesophilic, with an optimum temperature for mycelial growth in culture of about 20°C. Colonies on PDA produced masses of white aerial mycelium, with small white flocci distributed among sclerotia. After 2 weeks, sclerotia 0.5 to 4.5 mm in diameter were produced near the margin in a uniform distribution. Sclerotia were spherical, elongated, or fused to form irregular shapes and tightly attached to the agar surface by their under surface, which could be seen through the bottom of the petri dishes. DNA sequences of five replicates were obtained using the TianGen DNA secure plant kit. The internal transcribed spacer (ITS) region of rDNA was amplified with primers ITS1/ITS4 and sequenced. BLAST analysis of the 513-bp segment showed high similarity (99%) with a sequence of Sclerotinia nivalis (GenBank Accession No. AB516670). A representative sequence was deposited in GenBank (Accession No. JX294862). The fungus isolated from symptomatic tissues was identified as S. nivalis Saito on the basis of morphological and cultural characteristics (2,3) and ITS sequence analysis. Symptoms were reproduced in the greenhouse by inoculating the basal stem and roots of 15 atractylodes plants at the 7- to 10-leaf stage. Inoculum was prepared by macerating 14-day-old PDA cultures of the fungus in a blender and placing the mixture (approximately 20 g) into the potting medium of each plant. Sterile PDA was used to inoculate the five control plants. Plants were maintained in a greenhouse at 22 to 25°C and about 75% relative humidity. After 7 to 10 days, symptoms were similar to those in the fields. Lower leaves of inoculated plants became yellow and wilted, and infected plants died 2 weeks after inoculation, whereas control plants remained healthy. The pathogen was successfully recovered from symptomatic tissues, completing Koch's postulates. To our knowledge, this is the first report of Sclerotinia rot of Chinese atractylodes. Given its wide host range, S. nivalis has great potential to become an economically important plant pathogen. References: (1) W. G. Kim and W. D. Cho. Mycobiology 30:41, 2002. (2) G. Q. Li et al. Mycol. Res. 104:232, 2000. (3) I. Saito. Mycoscience 38:227, 1997.

The effect of selenium on the function of the anion transporter (Band 3) of erythrocyte membranes.

The transport activity of Band 3 of spectrin-stripped inside-out erythrocyte membrane vesicles (IOVs) or resealed ghosts was enhanced in the presence of trace amounts of Na2SeO3 (0.2-0.5 p.p.m.); however, at higher concentrations of Na2SeO3 (> 4.0 p.p.m.), an inverse result was obtained. Reassociation of spectrin with IOVs has no effect either on the transport activity of Band 3 or on the enhancement of its activity by Na2SeO3. Sulfhydryl reagents (p-chloromercuribenzoic acid and N-ethylmaleimide) could also inhibit Band 3 activity and eliminate the selenium effect. It is suggested that SH groups are involved in anion transport of Band 3 and that the selenium effect is based on the interaction of SH groups of Band 3 with Na2SeO3.

The role of Se in the interconversion of polymeric states of spectrin from human erythrocytes.

It has been shown that Se can markedly prevent the dissociation of spectrin from erythrocyte ghosts. We now report that the transformation of incubated spectrin oligomers to its tetramers and dimers was obviously decreased in the presence of trace amounts (0.5-2.0 p.p.m.) of Na2SeO3. The spectrin tetramers and dimers are in a reversible equilibrium and Se could alter this equilibrium in favour of tetramers. This Se effect is concentration dependent and an inverse result was obtained with higher Na2SeO3 concentrations (greater than 4.0 p.p.m.). We suggest that the equilibrium state of the spectrin tetramer-dimer may be governed by a conformation adjustment induced by Se and the difference in conformation in the presence of low and high Na2SeO3 concentration may lead to an alteration of the spectrin tetramer-dimer balance.

Reaction of Se with SH groups in spectrin is involved in the stabilization of erythrocyte membrane skeleton.

Na2SeO3 supplementation in the dialysis medium could obviously prevent the dissociation of spectrin from the erythrocyte membranes. Such Se effect could be eliminated by pretreatment of erythrocyte membranes with a SH-blocking reagent, iodoacetamide(IAA) or addition of a SH-compound, dithio-threitol. The fluorescence intensity of erythrocyte membranes labelled with the fluorescent probe N-(3-pyrenyl)-maleimide decreased with increasing Na2SeO3 concentration used for pretreatment of ghosts. 31P-NMR spectra of erythrocyte membrane dialyzed in the presence or absence of Na2SeO3 concentration showed a difference in chemical shift anisotropy (delta sigma) between these two samples. These data suggest that the stabilization effect is based on changes in lipid-protein interaction and conformation of membrane skeletal components induced by reaction of their SH groups with Na2SeO3.

Keshan disease--an endemic mitochondrial cardiomyopathy in China.

Keshan disease (KD) is a cardiomyopathy endemic in certain areas of China, characterized by severe deterioration and multiple focal necrosis. In the present paper we describe abnormalities of the structure and function of myocardial mitochondria from patients with subacute Keshan disease. Activities of succinate dehydrogenase, succinic oxidase, cytochrome c oxidase, H(+)-ATPase and its sensitivity to oligomycin and the response of membrane potential to energization by ATP were significantly decreased. However, the spectrum of reduced-minus-oxidized cytochromes in patients' mitochondria showed no obvious difference in the content of cytochrome c oxidase (aa3). There was also a marked decrease in lipid fluidity of affected mitochondria, and an abnormal amount of moderately electron dense amorphous inclusions. Electron-microscopic x-ray microanalysis and exposure to protein digestion reagent demonstrated that these inclusions are not Ca3(PO4)2, but are, probably, proteinaceous in nature. Affected mitochondria had markedly decreased selenium content. The defects in myocardial mitochondria from patients with chronic Keshan disease were less extensive than those in patients with subacute Keshan disease. We propose that Keshan disease be classified as a form of "mitochondrial cardiomyopathy".

Role of Se in stabilization of human erythrocyte membrane skeleton.

Na2SeO3 supplementation in the ageing medium could protect aged erythrocyte ghosts from decreases in lipid fluidity, Na, K-ATPase activity, and sensitivity to ouabain. Results also showed that Se could obviously prevent the dissociation of spectrin from the erythrocyte membrane. Furthermore, Se could markedly promote the reassociation of spectrin with the spectrin-stripped inside out membrane vesicles(IOVs) of erythrocytes. The protective action of Se on biomembranes is generally interpreted in terms of the activity of Se-containing glutathione peroxidase (GSHPx). However, since GSHPx is mainly distributed in the cytoplasm of erythrocytes, the stabilizing effect of Se on erythrocyte membranes might not be related to the activity of this enzyme.

Study on the interaction of Se and erythrocyte membrane--protective effect of Se on the erythrocyte membranes.

During the ageing of erythrocyte membrane, the spectrin content, Na,K-ATPase activity as well as the lipid fluidity are obviously decreased. However, supplementation of a trace amount of Na2SeO3 in the medium could prevent the dissociation of spectrin from membrane and delay the changes of Na,K-ATPase activity and lipid fluidity. The effectiveness is proportional to Se concentration within the range of 0.1-1.0 ppm. Similar effect of supplementation of Se on the intact erythrocytes during ageing has been also observed. The protective action of Se on biomembranes is generally interpreted in terms of the activity of Se-containing glutathione peroxidase (GSHPx). However, GSHPx mainly distributes in the cytoplasma of erythrocytes, therefore it seems that the protective action of supplemented Se on the isolated erythrocyte membrane might not be related to the activity of GSHPx.

Study on the interaction of Se and erythrocyte membrane--effect of Se on the Na, K-ATPase activity and fluidity of erythrocyte membranes.

The content of binding-Se in erythrocyte membrane may affect its structure and function. Decrease in Se content will lead to a lower activity of Na, K-ATPase and lipid fluidity in ghosts, and a marked increase in Na, K-ATPase activity as well as lipid fluidity of erythrocyte membrane was observed by supplementation of low concentration of Na2SeO3 (0.03-0.3 ppm Se), in vitro. This effect was obvious only when the ghosts were incubated with Se at 0-4 degrees C for at least half an hour prior to assay.