[Hot research topics on cardiovascular diseases in occupational population: a bibliometric analysis]

Objective: To investigate the literature characteristics and research topics on cardiovascular diseases in the occupational population quantitatively via a bibliometric analysis, and to provide a reference for the selection of research directions. Methods: A search strategy was developed according to the words in Medical Subject Heading (MeSH) , and PubMed database was searched for articles on cardiovascular diseases in the occupational population published from 2006 to 2015. The information of published year, authors, journals, and MeSH words was extracted, frequently used MeSH words were screened out, and a cluster analysis was performed for frequently used MeSH words. Results: A total of 1 272 articles were found, and about 150 articles were published annually from 2011 to 2015. Most articles were published in Occupational and Environmental Medicine, and the author Tohr Nilsson had the highest number of published articles. The influencing factors mainly included occupational mental stress, smoking, and working system, and the health outcomes attracting the most attention were hypertension, hand-arm vibration, ischemic heart disease, and myocardial infarction. The articles were clustered into 5 types, and 5 hot topics were summarized. Conclusion: The bibliometric analysis of cardiovascular diseases in occupational population shows that hypertension and hand-arm vibration are hot research topics, which can provide a reference to researchers.

Effects of glial cell line-derived neurotrophic factor and leukemia-inhibitory factor on the behavior of two calf testis germline stem cell colony types

Germline stem cells are the only such capable of transmitting genetic information in vivo. The isolation and culture of these cells in vitro provide a unique model to understand sperm differentiation and hence, spermatogenesis and male fertility. In this study, we isolated, purified, and cultured germline stem cells from the testes of newborn calves. Moreover, we investigated the effects of glial cell line-derived neurotrophic factor (GDNF) and leukemia-inhibitory factor (LIF) on their proliferation. Male calf germline stem cells were found to be pluripotent, and able to form grape-like and embryonic stem cell (ES)-like colonies when cultured. GDNF promoted proliferation of the former, whereas LIF induced growth of the latter. The grape-like colonies retained their germline stem cell characteristics, whereas the ES-like colonies demonstrated more primitive attributes. This investigation established a male calf germline stem cell culture model that may serve as a foundation for further studies aiming to understand the properties of such cells.

Benzoic acid beneficially affects growth performance of weaned pigs which was associated with changes in gut bacterial populations, morphology indices and growth factor gene expression

This study was conducted to investigate the effects of benzoic acid (BA) on growth performance, intestinal development and intestinal barrier function in weaned pigs. Ninety weaned pigs were randomly assigned to one of three treatments: a basal diet (CON), the basal diet supplemented with 2000 mg/kg benzoic acid (BA1) and 5000 mg/kg benzoic acid (BA2). At the end of days 14 and 42, six pigs per treatment were randomly selected to collect plasma and intestinal samples. Results showed that BA supplementation not only improved final body weight, daily growth and feed conversion ratio from days 15 to 42 and days 1 to 42, but also decreased the activity of plasma diamine oxidase (day 42) and the pH values of jejunal contents (day 14) (p < 0.05). Ileal Bacillus populations (day 14) were increased by BA, while Escherichia coli counts in the ileum and caecum (day 42) were decreased (p < 0.05). Higher Lactobacillus counts occurred in the ileum (day 14, 42) of BA1-fed piglets as compared to CON and BA2-fed piglets (p < 0.05). In addition, BA supplementation increased the ratio of villus height to crypt depth (day 14, 42) and decreased the crypt depth (day 14) (p < 0.05). Growth-stimulating factors (insulin-like growth factor-1, day 42; insulin-like growth factor-1 receptor, day 14, 42) and tight junction protein (occludin, day 14, 42; zonula occludens-1, day 42)-related gene mRNA levels were upregulated in the jejunum of piglets fed BA diets (p < 0.05). In conclusion, this study provides the first evidence that BA has beneficial effects on intestinal development and intestinal barrier function of weaned pigs, which can partly explain why growth performance of pigs was improved by dietary BA supplementation.

Intestinal microbiota could transfer host Gut characteristics from pigs to mice

BACKGROUND

The present study was conducted to compare the differences in gut microbiota composition and gut-phenotypes among pig breeds, and determine whether these differences would transmit to mice colonized with fecal microbiota of different pig breeds. A total of 24 1-day-old germ-free BALB/C mice were divided into 3 groups (TFM, YFM and RFM), which were transplanted with intact fecal microbiota of Tibetan pig (TP), Yorkshire pig (YP) and Rongchang pig (RP), respectively.

RESULTS

Results showed that different pig breeds exhibited distinct gut microbiota profile based on high-throughput pyrosequencing. YP exhibited a lower Firmicutes/Bacteroidetes ratio and apparent genera differences compared with RP and TP, and higher levels of bacteria from Spirochaetes were observed in TP compared with RP and YP (P < 0.05). Transplanted porcine microbiota into GF mice replicated the phenotypes of pig donors. Moreover, the three groups of donor pigs and their mice recipients exhibited different intestinal index and morphology. TP and RP had higher intestinal weight and relative CDX2 mRNA expression in ileum than YP, and longer intestine, higher villus height of duodenum and jejunum were observed in TP compared with YP and RP (P < 0.05). TP exhibited higher GLP-2 mRNA expression in duodenum and jejunum than RP (P < 0.05). Similarly, YFM had lower intestine weight and CDX2 mRNA expression in ileum than TFM and RFM (P < 0.05). The intestine length in TFM was longer than that in RFM, and TFM had higher villus height in duodenum and jejunum and GLP-2 mRNA expression in ileum than the other two groups (P < 0.05). Besides, the digestive and absorptive ability was different among the three groups in donor pigs and mice recipients. YP had higher jejunal lactase and maltase activities than TP and RP, while TP had higher activities of jejunal ATPase, γ-GT, and relative SGLT1 mRNA expression in duodenum and jejunum than YP and RP (P < 0.05). Likewise, YFM had higher jejunal sucrase and maltase activities than TFM and RFM, whereas higher jejunal γ-GT activity and relative SGLT1 mRNA expression in duodenum and ileum were observed in TFM compared with YFM and RFM (P < 0.05). In addition, Tibetan pigs-derived microbiota improved gut barrier in mice recipients. The concentration of MDA in YP was higher than that in TP and RP (P = 0.078), and the relative ZO-1 mRNA expression in ileum in TP was higher than that in YP (P < 0.05). Likely, compared with TFM and RFM, YFM exhibited increasing MDA concentration in jejunum (P = 0.098), and the relative ZO-1 mRNA expression in duodenum and ileum in TFM were higher than that in YFM (P < 0.05).

CONCLUSIONS

There were huge differences in gut microbiota composition and gut characteristics among pig breeds, and gut microbiota could partially convey host gut characteristics from pigs to mice.

Effects of dietary DL-2-hydroxy-4(methylthio)butanoic acid supplementation on growth performance, indices of ascites syndrome, and antioxidant capacity of broilers reared at low ambient temperature

This study examined the effects of dietary DL-2-hydroxy-4(methylthio)butanoic acid (DL-HMTBA) supplementation on growth performance, antioxidant capacity, and ascites syndrome (AS) in broilers reared at low ambient temperature (LAT) from 7 to 28 days of age. Eight hundred 7-day-old broilers were randomly assigned to two ambient temperatures (LAT and normal ambient temperature [NAT]), four supplemental DL-HMTBA levels (0.17, 0.34, 0.51, and 0.68 %) of the basal diet in a 2 × 4 factorial arrangement (ten replicate pens; ten birds/pen). LAT and NAT indicate temperatures of 12-14 and 24-26 °C in two chambers, respectively, and broilers were reared at these temperatures from 7 to 28 days of age. LAT significantly decreased body weight gain (P < 0.001), serum glutathione (GSH) content (day 14, P = 0.02; day 28, P = 0.045), glutathione peroxidase (GSH-Px) activity, and total antioxidant capacity (T-AOC) at 21 days (P = 0.001, 0.015) and 28 days (P = 0.017, 0.010) and increased feed conversion ratio (FCR) (P < 0.001), serum malondialdehyde (day 21, P = 0.000) and protein carbonyl Level (day 14, P = 0.003; day 21, P = 0.035). As for incidence of AS, there were significant effects of LAT on red blood cell (RBC) count (P < 0.05), hematocrit (HCT) (P < 0.05), and the right to total ventricular weight ratio (RV/TV) at 21 days (P = 0.012) and 28 days (P = 0.046). Supplementation of DL-HMTBA markedly decreased RV/TV at day 28 (P = 0.021), RBC (day 21, P = 0.008), HCT (day 21, P < 0.001), mean cell hemoglobin (day 14, P = 0.035; day 21, P = 0.003), and serum protein carbonyl level (day 21, P = 0.009), while significantly increased serum GSH content (day 14, P = 0.022; day 28, P = 0.001), SOD and GSH-Px activities at 21 days of age (P < 0.001 and P = 0.037). The optimal supplemental DL-HMTBA levels in basal diet of broilers aged from 7 to 28 days under low or normal temperatures were similar, so the authors recommended supplemental of DL-HMTBA level was 0.46 %.

Gut microbiome remodeling induces depressive-like behaviors through a pathway mediated by the host's metabolism

Major depressive disorder (MDD) is the result of complex gene-environment interactions. According to the World Health Organization, MDD is the leading cause of disability worldwide, and it is a major contributor to the overall global burden of disease. However, the definitive environmental mechanisms underlying the pathophysiology of MDD remain elusive. The gut microbiome is an increasingly recognized environmental factor that can shape the brain through the microbiota-gut-brain axis. We show here that the absence of gut microbiota in germ-free (GF) mice resulted in decreased immobility time in the forced swimming test relative to conventionally raised healthy control mice. Moreover, from clinical sampling, the gut microbiotic compositions of MDD patients and healthy controls were significantly different with MDD patients characterized by significant changes in the relative abundance of Firmicutes, Actinobacteria and Bacteroidetes. Fecal microbiota transplantation of GF mice with 'depression microbiota' derived from MDD patients resulted in depression-like behaviors compared with colonization with 'healthy microbiota' derived from healthy control individuals. Mice harboring 'depression microbiota' primarily exhibited disturbances of microbial genes and host metabolites involved in carbohydrate and amino acid metabolism. This study demonstrates that dysbiosis of the gut microbiome may have a causal role in the development of depressive-like behaviors, in a pathway that is mediated through the host's metabolism.

Amino acid, phosphorus, and energy digestibility of Aspergillus niger fermented rapeseed meal fed to growing pigs

Fermented rapeseed meal (FRSM) contains greater levels of protein and less glucosinolates, NDF, and phytic acid than rapeseed meal (RSM) and might be an attractive feedstuff for swine, but its nutritional value has been poorly characterized. The aim of this study was to evaluate the nutritional value of RSM fermented by for growing pigs. In Exp. 1, 6 barrows (21.20 ± 1.47 kg initial BW) fitted with a T-cannula in the distal ileum were allotted to a repeated 3 × 3 Latin square with 3 diets and 3 periods per square to determine the apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of CP and AA. A N-free diet and 2 diets containing RSM or FRSM as the only source of AA were formulated. Results indicated that there was no difference in AID and SID of CP and most AA between FRSM and RSM. However, the AID of 2 indispensable AA (Lys and Met) and 3 dispensable AA (Asp, Gly, and Tyr) were greater (P < 0.05) for FRSM than for RSM. The SID of only 2 dispensable AA (Gly and Tyr) were greater (P < 0.05) for FRSM than for RSM. In Exp. 2, 16 barrows (32.57 ± 2.67 kg initial BW) were allotted to 2 diets formulated to contain RSM or FRSM as the sole source of P to determine the apparent total tract digestibility (ATTD) of P. The ATTD and standardized total tract digestibility (STTD) of P in FRSM were 72.10 and 77.31%, respectively. These values were greater (P < 0.01) than in RSM (34.79 and 41.34%, respectively). In Exp. 3, 24 growing barrows (32.23 ± 1.33 kg initial BW) were fed 3 diets with 8 replicate pigs per diet to measure concentration of DE and ME of FRSM. A corn diet consisting of 98.40% corn was formulated and 2 additional diets were formulated by mixing corn with 35% RSM or FRSM. The DE and ME in FRSM (2,887 and 2,650 kcal/kg of DM, respectively) were greater (P < 0.05) than those in RSM (2,609 and 2,328 kcal/kg of DM, respectively). In summary, solid-state fermentation of RSM by has a greater nutritional value than RSM and is a promising alternative high-quality protein source.

Hawthorn leaf flavonoids alleviate nonalcoholic fatty liver disease by enhancing the adiponectin/AMPK pathway

Hawthorn (Crataeguspinnatifida) belongs to the genus Rosaceae family of plants. The hawthorn leaf, Crataeguspinnatifida Bunge, is used for both condiment and medicinal purposes to prevent and treat metabolic dysfunctions, such as hyperlipidemia, hypertension, and cardiovascular disease in traditional Chinese medicine. However, its effects on nonalcoholic fatty liver disease (NAFLD) remain obscure. The purpose of the present study was to investigate the protective effect of hawthorn leaf flavonoids (HLF), the dominant bioactive extracts of hawthorn leaves, on high fat diet (HFD)-induced hepatic steatosis and to elucidate its underlying mechanisms. HLF supplementation significantly lowered body weight, liver weight, liver/body weight ratio, improved serum parameters and liver dysfunction and markedly decreased hepatic lipid accumulation in HFD-fed rats. In addition, HLF intervention dramatically increased circulating adiponectin levels and up-regulated the expression of adiponectin receptors, particularly adiponectin receptor 2 (AdipoR2) in the liver. Moreover, adenosine monophosphate (AMP)-activated protein kinase (AMPK) was also activated, as well as AMPK-mediated alteration of sterol regulatory element binding protein-1c (SREBP-1c), peroxisome proliferator-activated receptor α (PPARα) and their downstream targets. Taken together, our data suggest that HLF ameliorates hepatic steatosis by enhancing the adiponectin/AMPK pathway in the liver of HFD-induced NAFLD rats.

Randomised clinical trial: the clinical efficacy and safety of an alginate-antacid (Gaviscon Double Action) versus placebo, for decreasing upper gastrointestinal symptoms in symptomatic gastroesophageal reflux disease (GERD) in China

BACKGROUND

There is a paucity of large-scale studies evaluating the clinical benefit of the Gaviscon Double Action (DA) alginate-antacid formulation for treating gastroesophageal reflux disease (GERD) symptoms.

AIM

Randomised double-blind placebo-controlled parallel-group study to evaluate efficacy and safety of Gaviscon DA in reducing heartburn, regurgitation and dyspepsia symptoms in individuals with mild-to-moderate GERD in China.

METHODS

Participants with symptomatic GERD (n = 1107) were randomised to receive Gaviscon DA or placebo (two tablets four times daily) for seven consecutive days. The primary endpoint compared the change in Reflux Disease Questionnaire (RDQ) score for the GERD (heartburn + regurgitation) dimension between Gaviscon DA and placebo. Secondary endpoints compared the change in RDQ scores for individual heartburn, regurgitation and dyspepsia dimensions, overall treatment evaluation (OTE) scores and incidence of adverse events (AEs).

RESULTS

Mean RDQ GERD scores: 2.51 for Gaviscon DA and 2.50 for placebo at baseline; 1.25 for Gaviscon DA and 1.46 for placebo post treatment. Gaviscon DA was statistically superior to placebo in reducing GERD and dyspepsia RDQ scores [least-squares mean (LSM) difference: GERD -0.21, P < 0.0001; dyspepsia -0.18, P = 0.0004], despite a substantial placebo response. The Gaviscon DA group reported more favourable overall treatment responses than the placebo group across all OTE categories (P < 0.0001). Superior relief of GERD symptoms was observed both in those with non-erosive and those with erosive reflux disease (LSM difference -0.14 [P = 0.038] and -0.29 [P < 0.0001] respectively). Incidence of AEs was similar in both groups.

CONCLUSION

Gaviscon DA tablets provide effective and safe reduction in acid reflux and dyspepsia symptoms in Chinese individuals with mild-to-moderate GERD. ClinicalTrials.gov: NCT01869491.

DAMGO depresses inhibitory synaptic transmission via different downstream pathways of μ opioid receptors in ventral tegmental area and periaqueductal gray

Opioid-induced rewarding and motorstimulant effects are mediated by an increased activity of the ventral tegmental area (VTA) dopamine (DA) neurons. The excitatory mechanism of opioids on VTA-DA neurons has been proposed to be due to the depression of GABAergic synaptic transmission in VTA-DA neurons. However, how opioids depress GABAergic synaptic transmission in VTA-DA neurons remain to be studied. In the present study, we explored the mechanism of the inhibitory effect of [D-Ala(2), N-Me-Phe(4), Gly(5)-ol]-enkephalin (DAMGO) on GABAergic synaptic transmission in VTA-DA neurons using multiple approaches and techniques. Our results showed that (1) DAMGO inhibits GABAergic inputs in VTA-DA neurons at presynaptic sites; (2) effect of DAMGO on GABAergic inputs in VTA-DA neurons is inhibited by potassium channel blocker 4-aminopyridine (4-AP) and Gi protein inhibitor N-ethylmaleimide (NEM); (3) phospholipase A2 (PLA2) does not mediate the effect of DAMGO on GABAergic inputs in VTA-DA neurons, but mediates it in the periaqueductal gray (PAG); (4) multiple downstream signaling molecules of μ receptors do not mediate the effect of DAMGO on GABAergic inputs in VTA-DA neurons. These results suggest that DAMGO depresses inhibitory synaptic transmission via μ receptor-Gi protein-Kv channel pathway in VTA-DA neurons, but via μ receptor-PLA2 pathway in PAG neurons.

Component-Resolved Diagnostic Study of Dermatophagoides Pteronyssinus Major Allergen Molecules in a Southern Chinese Cohort

BACKGROUND AND OBJECTIVE

Little is known about component-resolved diagnosis (CRD) for Dermatophagoides pteronyssinus (Der p) sensitization in the Chinese population. We aimed to evaluate sensitization to Der p components in southern China.

METHODS

Two-hundred immunotherapy-naïve patients with asthma and/or rhinitis positive to specific IgE (sIgE) against Der p extract, along with 20 Der p-negative nonallergic healthy controls, were tested for sIgE against Der p 1, Der p 2, and Der p 10 using ImmunoCAP 100. Seventy-five were further examined with the ImmunoCAP Immuno Solid-phase Allergen Chip (ISAC). Der p 10-positive patients were also tested for sIgE against crude extracts of cockroach, moth, and shrimp.

RESULTS

In total, 183 (91.5%) of the 200 patients were sensitized to Der p 1 and/or Der p 2. The proportion of positive results and the median level of s1gE against Der p 1 were higher in children than in adults. Der p 1 and Der p 2 correlated with Der p in sIgE levels. ImmunoCAP ISAC demonstrated 100% specificity and 84% sensitivity in detecting Der p 1, Der p 2, and Der p 10 compared with ImmunoCAP 100. Sensitization to Der p 10 correlated well with sIgE to shrimp, moths, cockroaches, Pen m 1, Bla g 7, and Ani s 3.

CONCLUSIONS

The detection of Der p 1 and Der p 2 provided a good reflection of atopy to Der p in a Chinese cohort. Sensitization to Der p 10 may result from cross-reactivity with seafood and cockroaches in coastal southern China. ImmunoCAP ISAC may be a useful tool for CRD, with comparable performance to ImmunoCAP 100.

Effect of Different Matrix Metalloproteinase Inhibitors on Microtensile Bond Strength of an Etch-and-Rinse and a Self-etching Adhesive to Dentin

Aim

This study aimed to analyze the effect of different matrix metalloproteinase (MMP) inhibitors on the microtensile bond strength (microTBS) of an etch-and-rinse and a self-etching adhesive after 9 months of aging.

Methods and Materials

Flat human dentin surfaces were bonded either with an etch-and-rinse adhesive (Optibond FL) or a self-etching adhesive (Clearfil SE Bond). Dentin surfaces were left untreated or were pretreated with MMP inhibitors (2% chlorhexidine digluconate [CHX], 0.05% green tea extract, 1 mM ferrous sulfate, or 0.2 mM galardin) prior to application of the adhesive. Composite buildups were made incrementally. Pretreated groups were tested after 9 months of storage in artificial saliva (37°C) and compared with untreated groups, which were tested immediately (initial microTBS) and upon aging (9-month microTBS). Data were analyzed by linear mixed-model regression. Failure mode analysis was performed microscopically and statistically analyzed by repeated-measures analysis of variance (p&lt;0.05).

Results

MicroTBS of the etch-and-rinse adhesive but not of the self-etching adhesive was significantly decreased by aging. For Optibond FL, pretreatment with 2% CHX, 0.05% green tea extract, and 0.2 mM galardin revealed bond strength values (MPa) similar to the initial microTBS (32.1±14.8) and significantly higher compared with the microTBS (20.3±13.6) of aged untreated dentin. No significant differences were observed between groups bonded with Clearfil SE Bond (initial microTBS: 28.3±12.4; 9-month microTBS: 25.3±11.8). Application of the MMP inhibitors decreased the number of adhesive failures compared with untreated controls after 9 months of aging, but this effect was not significant.

Conclusion

The MMP inhibitors prevented the decrease in microTBS upon aging of the etch-and-rinse but not of the self-etching adhesive.

The charge carrier localization in the cubic perovskite BaOsO3 revealed by an optical study

We present the optical conductivity spectra for the newly discovered cubic perovskite structure BaOsO3 at various temperatures. The compound exhibits metallic behaviour above 50 K, but becomes non-metallic below 50 K. However, below 550 cm(-1), neither the typical Drude response nor an energy gap is observed in optical conductivity spectra from 300 K to 10 K. A broad peak centred at about 550 cm(-1) is observed in the real part of optical conductivity σ1(ω). The structure could be well reproduced by the localization modified Drude model. The life time of the carrier, deduced from σ1(ω) in terms of the localization modified Drude model, decreases with T varying from 300 K to 100 K, then increases slightly at 10 K. The study indicates that the compound is at the boundary of metal-insulator transition.

Racial/ethnic differences in hip and diaphyseal femur fractures

Contemporary femur fracture rates were examined in northern California women and compared by race/ethnicity. During 2006-2012, hip fracture rates declined, but diaphyseal fracture rates increased, especially in Asians. Women with diaphyseal fracture were younger and more likely to be bisphosphonate-treated. These disparities in femur fracture should be further examined.

INTRODUCTION

The epidemiology of diaphyseal femur fracture differs from proximal femur (hip) fracture, although few studies have examined demographic variations in the current era. This study examines contemporary differences in low-energy femur fracture by race/ethnicity in a large, diverse integrated health-care delivery system.

METHODS

The incidence of hip and diaphyseal fracture in northern California women aged ≥50 years old during 2006-2012 was examined. Hip (femoral neck and pertrochanteric) fractures were classified by hospital diagnosis codes, while diaphyseal (subtrochanteric and femoral shaft) fractures were further adjudicated based on radiologic findings. Demographic and clinical data were obtained from health plan databases. Fracture incidence was examined over time and by race/ethnicity.

RESULTS

There were 10,648 (97.3 %) hip and 300 (2.7 %) diaphyseal fractures among 10,493 women. The age-adjusted incidence of hip fracture fell from 281 to 240 per 100,000 women and was highest for white women. However, diaphyseal fracture rates increased over time, with a significant upward trend in Asians (9 to 27 per 100,000) who also had the highest rate of diaphyseal fracture. Women with diaphyseal fracture were younger than women with hip fracture, more likely to be of Asian race and to have received bisphosphonate drugs. Women with longer bisphosphonate treatment duration were also more likely to have a diaphyseal fracture, especially younger Asian women.

CONCLUSION

During 2006 to 2012, hip fracture rates declined, but diaphyseal fracture rates increased, particularly among Asian women. The association of diaphyseal fracture and bisphosphonate therapy should be further investigated with examination of fracture pattern.