Different impact of short-term and long-term hindlimb disuse on bone homeostasis

Disuse osteoporosis is one of the major problems of bone health which commonly occurs in astronauts during long-term spaceflight and bedridden patients. However, the mechanisms underlying such mechanical unloading induced bone loss have not been fully understood. In this study, we employed hindlimb-unloading mice models with different length of tail suspension to investigate if the bone loss was regulated by distinct factors under different duration of disuse. Our micro-CT results showed more significant decrease of bone mass in 6W (6-week) tail-suspension mice compared to the 1W (1-week) tail-suspension ones, as indicated by greater reduction of BV/TV, Tb.N, B.Ar/T.Ar and Ct.Th. RNA-sequencing results showed significant effects of hindlimb disuse on cell locomotion and immune system process which could cause bone loss.Real-time quantitative PCR results indicated a greater number of bone formation related genes that were downregulated in short-term tail-suspension mice compared to the long-term ones. It is, thus, suggested while sustained hindlimb unloading continuously contributes to bone loss, molecular regulation of bone homeostasis tends to reach a balance during this process.

Dihydrocapsaicin suppresses the STING-mediated accumulation of ROS and NLRP3 inflammasome and alleviates apoptosis after ischemia-reperfusion injury of perforator skin flap

Avascular necrosis frequently occurs as a complication following surgery involving the distal perforator flap. Dihydrocapsaicin (DHC) can protect tissue from ischemia-reperfusion (I/R) injury, but its specific role in multizone perforator flaps remains unclear. In this study, the prospective target of DHC in the context of I/R injury was predicted using network pharmacology analysis. Flap viability was determined through survival area analysis, laser Doppler blood flow, angiograms, and histological examination. The expressions of angiogenesis, apoptosis, NLR family pyrin domain containing 3 (NLRP3) inflammasome, oxidative stress, and molecules related to cyclic guanosine monophosphate (GMP)-adenosine monophosphate synthase (cGAS)-interferon gene stimulant (STING) pathway were assessed using western blotting, immunofluorescence, TUNEL staining, and dihydroethidium (DHE) staining. Our finding revealed that DHC promoted the perforator flap survival, which involves the cGAS-STING pathway, oxidative stress, NLRP3 inflammasome, apoptosis, and angiogenesis. DHC induced oxidative stress resistance and suppressed the NLRP3 inflammasome, preventing apoptosis in vascular endothelial cells. Through regulation of STING pathway, DHC controlled oxidative stress in endothelial cells and NLRP3 levels in ischemic flaps. However, activation of the cGAS-STING pathway led to the accumulation of reactive oxygen species (ROS) and NLRP3 inflammasome, thereby diminishing the protective role of DHC. DHC enhanced the survival of multidomain perforator flaps by suppressing the cGAS-STING pathway, oxidative stress, and the formation of NLRP3 inflammasome. These findings unveil a potentially novel mechanism with clinical significance for promoting the survival of multidomain perforator flaps.

Role of low-density lipoprotein in mediating the effect of air pollution on coronary heart disease: a two-step multivariate Mendelian randomization study

OBJECTIVE

Air pollution is affecting the health of millions of people all over the world. The causal correlations of PM2.5, PM10, and nitrogen dioxide (NOx), as the main fine particulate matter, and coronary heart disease (CHD) are yet to be explored. Low-density lipoprotein (LDL) has been a principal factor in the pathogenesis of CHD. It is an interesting issue to consider whether LDL mediates the effect of air pollutants in CHD pathogenesis.

MATERIALS AND METHODS

A genome-wide association study (GWAS) on the European population, followed up from 2010 to 2018, involving over 400,000 participants, was based on a land-use regression model. The annual mean concentrations of major air pollutant particles, PM2.5 (n=423,796), PM10 (n=423,796), and NOx (n=456,380), were recorded. The large GWAS database of CHD covered over ten million SNPs with independent single nucleotide polymorphisms (SNPs). LDL database collected major biochemical blood parameters from over 400,000 patients (n=440,546). Taken together, we conducted independent two-sample Mendelian randomization (MR) analyses for the causality between air pollutants (PM2.5, PM10, and NOx) and CHD. Multivariate MR analysis was conducted using causal relationships to determine the direct effects of exposure on outcome. The fixed-effect inverse variance weighted (IVW2) method was mainly employed to assess this relationship, with a confidence interval of 95% for the odds ratio (OR). Also, MR-Egger, weighted median, maximum likelihood ratio method, and random-effects inverse variance-weighted (IVW1) method were adopted as supplementary methods.

RESULTS

Two-sample MR results based on the IVW2 method suggested positive correlations between PM2.5 and CHD [OR 1.875 (1.279-2.748), p=0.001], PM10 and CHD [OR 2.586 (1.479-4.523), p=0.001], and NOx and CHD [OR 2.991 (2.021-4.427), p=4.37E-08]. The direct effect and mediating proportion were calculated using multivariable Mendelian randomization (MVMR). Lastly, the mediating proportions of LDL in the regulatory roles of PM2.5, PM10, and NOx in CHD were 2.82%, 4.73%, and 9.54%, respectively.

CONCLUSIONS

PM2.5, PM10, and NOx share direct causal associations with CHD, and LDL performs a mediating role in this pathogenic process. Early prevention against air pollution (such as increasing green areas and reducing large-scale industrial dust emissions) and early lipid-lowering treatment can effectively prevent the occurrence of CHD.

Tetrahydropalmatine: Orchestrating survival - Regulating autophagy and apoptosis via the PI3K/AKT/mTOR pathway in perforator flaps

BACKGROUND

Introduced in clinical practice in 1989, perforator flaps are vital for tissue defect repair, but they are challenged by distal necrosis. Tetrahydropalmatine (THP) from celandine is renowned for its anti-inflammatory and analgesic effects. This study investigates THP's use in perforator flaps.

METHODS

Thirty rats were divided into a control group and four THP concentration groups, while seventy-eight rats were categorized as control, THP, THP combined with rapamycin (RAP), and RAP alone. We created 11 cm by 2.5 cm multi-regional perforator flaps on rat backs, assessing survival blood flow and extracting skin flap tissue for autophagy, oxidative stress, apoptosis, and angiogenesis markers.

RESULTS

The THP group exhibited significantly reduced distal necrosis, increased blood flow density, and survival area on the seventh day compared to controls. Immunohistochemistry and Western blot results demonstrated improved anti-oxidative stress and angiogenesis markers, along with decreased autophagy and apoptosis indicators. Combining THP with RAP diminished flap survival compared to THP alone. This was supported by protein expression changes in the PI3K-AKT-mTOR pathway.

CONCLUSION

THP enhances flap survival by modulating autophagy, reducing tissue edema, promoting angiogenesis, and mitigating apoptosis and oxidative stress. THP offers a potential strategy for enhancing multi-regional perforator flap survival through the PI3K/AKT/mTOR pathway. These findings highlight THP's promise in combatting perforator flap necrosis, uncovering a novel mechanism for its impact on flap survival.

Impact of COVID-19 infection experience on mental health status of intensive care unit patients' family members: a real-world study

PURPOSE

Family members of patients hospitalized in intensive care unit (ICU) are susceptible to adverse psychological outcomes. However, there is a paucity of studies specifically examining the mental health symptoms in ICU patients' family members with a prior history of coronavirus disease 2019 (COVID-19) infection.

AIM

This study aimed to investigate mental health status and its influencing factors of ICU patients' family members with previous COVID-19 infection experience in China.

DESIGN

Nationwide, cross-sectional cohort of consecutive participants of family members of ICU patients from 10 provinces randomly selected in mainland China conducted between October 2022 and May 2023.

METHODS

The basic information scale, Self-rating depression scale, Self-rating Anxiety Scale, Impact of Event Scale-Revised, Pittsburgh sleep quality index, Perceived Stress Scale, Connor-Davidson resilience scale, Simplified Coping Style Questionnaire were employed to explore mental health status among participants.

RESULTS

A total of 463 participants, comprising 156 individuals in Covid-19 family member cohort (infection group) and 307 individuals in control family member cohort (control group), met inclusion criteria. The infection group exhibited significantly higher incidence of composite mental health symptoms compared to control group (P = 0.017). Multivariable logistic regression analysis revealed that being female, engaging in physical/mental labor, residing in rural areas, and having children were identified as risk factors for the development of depression, anxiety, and post-traumatic stress disorder symptoms, while medical history of surgery was protective factor. A predictive model demonstrated a favorable discriminative ability and excellent calibration.

CONCLUSION

COVID-19 infection experience regarded as new traumatic stressors worsen mental health status of ICU patients' family members.

Risk factors for bloodstream infection in paediatric haematopoietic stem cell transplantation: a systematic review and meta-analysis

BACKGROUND

Haematopoietic stem cell transplantation (HSCT), a standard treatment for paediatric haematological diseases, is highly associated with bloodstream infection (BSI), which may increase mortality.

AIM

To explore the risk factors for BSI in paediatric HSCT recipients.

METHODS

Three English databases and four Chinese databases were searched from inception to March 17th, 2022. Eligible studies included randomized controlled trials, cohort studies, and case-control studies that enrolled HSCT recipients aged ≤18 years and reported BSI risk factors. Two reviewers independently screened studies, extracted data, and assessed the risk of bias. Using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE), certainty of body of evidence was assessed.

FINDINGS

Fourteen studies involving 4602 persons were included. The incidences of BSI and associated mortality in paediatric HSCT recipients were approximately 10-50% and 5-15%, respectively. Meta-analysis of all studies revealed that previous BSI before HSCT (relative effect (RE): 2.28; 95% confidence interval (CI) 1.19-4.34, moderate certainty) and receiving an umbilical cord blood transplant (RE: 1.55; 95% CI: 1.22-1.97, moderate certainty) were probably associated with an increased risk of BSI. Meta-analysis of studies with low risk of bias reassured that previous BSI before HSCT probably increased the risk of BSI (RE: 2.28; 95% CI: 1.19-4.34, moderate certainty), and revealed that steroid use (RE: 2.72; 95% CI: 1.31-5.64, moderate certainty) was likely a risk factor whereas autologous HSCT was probably a protective factor of BSI (RE: 0.65; 95% CI: 0.45-0.94, moderate certainty).

CONCLUSION

These findings could inform the management of paediatric HSCT recipients, helping identify who may benefit from prophylactic antibiotics.

Simulating nitrogen balance in Canadian agricultural soils from 1981 to 2016

Agriculture produces food, fiber and biofuels for the world's growing population, however, agriculture can be a major contributor of nitrogen (N) losses including emissions of ammonia (NH₃), nitrous oxide (N₂O) and nitrate (NO₃^-) leaching and runoff. A Canadian Agricultural Nitrogen Budget for Reactive N (CANBNr) model was developed to estimate the soil N balance in 3487 soil landscape of Canada polygons from 1981 to 2016. The CANBNr model integrates NH₃ emission from fertilizers, manure from housing, storage and field, as well as direct/indirect N₂O emissions from fertilizers, manures, crop residues and soil organic matter. The NO₃^- leaching is estimated based on the residual soil N (RSN) at harvest and drainage derived with the DeNitrification-DeComposition (DNDC) model. From 1981 to 2016, the N input from fertilizer and N fixation increased at a greater rate than N removal in harvested crops in all provinces of Canada, resulting in an increase in the RSN and N losses. In 2016, the Prairie provinces had lower N losses (11.7 kg N ha^-1) from N₂O, NH₃ and NO₃^- compared with 43.2 kg N ha^-1 in central Canada, and 76.5 kg N ha^-1 in Atlantic Canada. However, the Prairie provinces had 84.3% of the total Canadian farmland (74.3% of the total Canadian N input), while central Canada had 12.9% of Canadian farmland (21.7% of the total Canadian N input). In the Prairie provinces, the total N₂O loss from fertilizer N ranged 4.4-8.6 Gg N whereas NH₃ loss ranged from 17.1 to 44.6 Gg N and these values were influenced by both emission intensity and total land area. Total N₂O losses from manure were highest in Alberta, Ontario and Quebec resulting in 4.8, 4.4, and 3.4 Gg N and NH₃ losses from manure were also highest in these 3 provinces at 61.1, 45.2 and 40.4 Gg N, respectively. Nitrate leaching was impacted by drainage volumes, soil type and N inputs. In the non-growing season, NO₃^- leaching losses (36-yr average) were 63.3 Gg in Ontario and 57.5 Gg N in Quebec compared with 20.8 Gg N for Ontario and 35.5 Gg N for Quebec in the growing season. In contrast, the Prairie provinces showed higher NO₃^- leaching in the growing season (23.1-37.4 Gg N) than in the non-growing season (10.4-13.7 Gg N). In summary, total fertilizer N increased the most over the 36 years in the Prairies which resulted in increased RSN and N leaching losses that will require further intervention.

The safety of human embryos following long-term cryopreservation ( >6 years) on vitrification

BACKGROUND

Vitrification of embryos has become the basic means of assisted reproductive technology (ART) therapy in recent years. Concerns have also been raised about the safety of vitrification and the effect of cryopreservation time. Most of the previous studies were on the data within 6 years of cryopreservation.

OBJECTIVE

In this study, we aimed to evaluate the impact of long-term cryopreservation (>6 years) on pregnancy and neonatal outcomes.

MATERIALS AND METHODS

This research was a single-center, retrospective analysis, including 426 frozen-thawed embryo transfer (FET) cycles. Patients who participated in IVF-FET cycles between January 2013 to December 2020 were analyzed. Preferentially matched participants were divided into three groups according to storage time: group A (>72 months), group B (0-3 months, propensity score matching [PSM] according to the age of oocyte retrieval), and group C (0-3 months, PSM according to the age of embryo transfer).

RESULTS

Our results revealed that there were no significant differences in human chorionic gonadotropin [HCG] positive rate, clinical pregnancy rate, miscarriage rate, live birth rate, and neonatal outcomes when the embryo storage duration >72 months. But the proportion of high birth weight was higher in group A (>72 months) when matched according to age at embryo transfer.

CONCLUSION

The results of our study showed that long-term cryopreservation had no effect on the pregnancy and neonatal outcomes of vitrification. The results offer evidence for the safety of using long-term cryopreservation embryos after vitrification. DOI: 10.54680/fr23310110612.

Valgus-varus deformity induced abnormal tissue metabolism, inflammatory damage and apoptosis in broilers

1. This study explored the tissue metabolic status and the relationship with inflammation in valgus-valgus deformity (VVD) broilers with increasing age.2. Tissue and blood from VVD and healthy broilers were collected at two, four and five weeks old. A fully automated biochemical analyser, real-time PCR, HE staining and enzyme-linked immunosorbent assay were used to detect tissue metabolic indexes, mRNA levels of inflammation and apoptosis cytokines in immune organs, histological changes and serum inflammation and immune-related protein contents in VVD broilers.3. The results showed that VVD increased the levels of total protein, albumin, alanine aminotransferase at five weeks of age, aspartate aminotransferase, urea and creatine kinase in blood at two weeks of age. It upregulated the gene expression of inflammatory factors IL-1β, IL-6, IL-8, TNF-α, NF-κB and TGF-β and apoptotic factors FAS, Bcl-2, caspase-3 and 9 in immune organs; increased levels of serum proteins TNF-α, IL-1β and IL-6 and decreased levels of serum immunoglobulins IgY and CD3⁺.4. In addition, with increasing age, IL-10 gene expression gradually increased in the BF and decreased in the spleen.5. In conclusion, VVD broilers have disorders of liver and kidney metabolism, inflammation and apoptosis of immune organs and increased levels of serum inflammatory factor proteins.

[Clonality relatedness and molecular characteristics of Richter transformation]

Objective: To investigate the clinical, genetic, and clonality related aspects of individuals with Richter transformation (RT) . Methods: From January 2019 to December 2021, 18 RT patients with diagnoses at the First Affiliated Hospital of Nanjing Medical University (Pukou CLL center) were retrospectively examined. The immunoglobin heavy variable (IGHV) gene usage and IGHV-D-J rearrangement pattern of diagnosed CLL/SLL and transformed diffuse large B-cell lymphoma (DLBCL) were compared to determine the clonality relatedness. To investigate the risk factors of RT, Clinical and laboratory data from patients with newly diagnosed CLL/SLL and transformed DLBCL were gathered. Results: The median age of RT was 56.5 (41-75) years old. 17 patients transformed to DLBCL and 1 transformed to Hodgkin lymphoma (HL) . Of 17 individuals who had DLBCL transformation, 15 had CLL/SLL-related clonality and 2 had unrelated clonality. Next-generation sequencing (NGS) analysis of 11 paired initially diagnosed treatment-naive CLL/SLL and RT DLBCL found that EGR2、TP53 and NOTCH1 were among the most frequently mutated genes both in treatment-naive CLL/SLL and in RT DLBCL. In several cases, specific mutations were gained or lost throughout RT, indicating clonal evolution. Among 10 patients before exposure to BTK inhibitors before RT, four patients acquired BTK mutation. The aforementioned mutations should be considered high-risk variables for transformation; in addition, TP53 and EGR2 mutations could be linked to a poor prognosis following RT in patients receiving a cocktail of new medicines. Conclusion: Most RT DLBCL patients in our center are clonality related (15/17, 88.2% ) and we recommend all qualified centers to evaluate clonality relatedness of RT DLBCL patients. There was some variability in the mutational landscape between DLBCL that had undergone a transformation and initially diagnosed, treatment-naive CLL/SLL. The underlying molecular mechanism of RT needs more research.

MSX1 Drives Tooth Morphogenesis Through Controlling Wnt Signaling Activity

Tooth agenesis is a common structural birth defect in humans that results from failure of morphogenesis during early tooth development. The homeobox transcription factor Msx1 and the canonical Wnt signaling pathway are essential for "bud to cap" morphogenesis and are causal factors for tooth agenesis. Our recent study suggested that Msx1 regulates Wnt signaling during early tooth development by suppressing the expression of Dkk2 and Sfrp2 in the tooth bud mesenchyme, and it demonstrated partial rescue of Msx1-deficient molar teeth by a combination of DKK inhibition and genetic inactivation of SFRPs. In this study, we found that Sostdc1/Wise, another secreted Wnt antagonist, is involved in regulating the odontogenic pathway downstream of Msx1. Whereas Sostdc1 expression in the developing tooth germ was not increased in Msx1-/- embryos, genetic inactivation of Sostdc1 rescued maxillary molar, but not mandibular molar, morphogenesis in Msx1-/- mice with full penetrance. Since the Msx1-/-;Sostdc1-/- embryos exhibited ectopic Dkk2 expression in the developing dental mesenchyme, similar to Msx1-/- embryos, we generated and analyzed tooth development in Msx1-/-;Dkk2-/- double and Msx1-/-;Dkk2-/-;Sostdc1-/- triple mutant mice. The Msx1-/-;Dkk2-/- double mutants showed rescued maxillary molar morphogenesis at high penetrance, with a small percentage also exhibiting mandibular molars that transitioned to the cap stage. Furthermore, tooth development was rescued in the maxillary and mandibular molars, with full penetrance, in the Msx1-/-;Dkk2-/-;Sostdc1-/- mice. Together, these data reveal 1) that a key role of Msx1 in driving tooth development through the bud-to-cap transition is to control the expression of Dkk2 and 2) that modulation of Wnt signaling activity by Dkk2 and Sostdc1 plays a crucial role in the Msx1-dependent odontogenic pathway during early tooth morphogenesis.

Formononetin Improves the Survival of Random Skin Flaps Through PI3K/Akt-Mediated Nrf2 Antioxidant Defense System

Random-pattern skin flap is widely used in plastic and reconstructive surgery. However, its clinical effect is limited by ischemia necrosis occurs at the distal part of flap. Previous studies have proved that the protective effect of formononetin was associated with its antioxidant, anti-inflammatory ability. However, further research is still needed on the effect of formononetin on flap viability. The purpose of our study was to investigate the effect of formononetin on flap survival and the underlying mechanisms. Two doses (25 mg/kg, 50 mg/kg)of formononetin were administered for seven consecutive days on flap model. Flap tissues were collected on postoperative day 7. Our results revealed that formononetin promoted skin flap viability in a dose-dependent manner. Using immunohistochemical staining and western blot, we found that formononetin significantly reduced oxidative stress and inflammation. Hematoxylin and eosin (H and E) staining, laser Doppler images and immunofluorescence staining showed the enhancement of angiogenesis after formononetin treatment. Mechanistically, we demonstrated that the antioxidation of formononetin was mediated by activation and nuclear translocation of nuclear factor-E2-related factor 2 (Nrf2), while down-regulating cytoplasmic Kelch-like ECH-associated protein 1 (Keap1) expression. Co-treatment with formononetin and LY294002 (15 mg/kg), a potent Phosphatidylinositol-3-kinase (PI3K) inhibitor, which aborted nuclear Nrf2 expression and phosphorylated Akt, indicating that formononetin-mediated Nrf2 activation was related to PI3K/Akt pathway. Overall, our findings revealed that formononetin increased angiogenesis, reduced oxidative stress and inflammation, thus promoting flap survival. We highlighted the antioxidant effects of formononetin since the Nrf2 system was activated. Therefore, formononetin might be a promising candidate drug that can enhance survival of skin flaps.

Seasonal Variation of Zooplankton Communities and the Effects of Environmental Factors in the Seawater Near Taishan Nuclear Power Station

In the seawater near Taishan Nuclear Power Station, Zooplankton community composition and abundance, the biomass of major taxa, vertical distribution pattern, together with several environmental factors were investigated to evaluate the variation tendency as the seasons change. The structure characteristics of the zooplankton community were analyzed by Margalef species richness (d), Shannon-wiener species diversity index (H’), Pielou evenness index(J’), zooplankton dominant (Y), and dominant species replacement rate (R). There are 48 species within 11 classes of zooplankton identified, including 32 species of copepods. Zooplankton species richness changed obviously in the four seasons, Spring saw the highest (8010.00 ind.m-3), followed by winter (5100.00 ind.m-3), autumn (1713.75 ind.m-3), and summer (1196.25 ind.m-3). Similar trends were observed for the wet biomass, which was highest in spring (215.90 mg.m-3), followed by winter (181.70 mg.m-3), summer (78.56 mg.m-3), and autumn (24.69 mg.m-3), which gave an annual average of 125.21 mg.m-3. The results indicate that the abundance and biomass in spring were significantly higher than those in other seasons. Altogether 8 dominant species were identified along the whole year: Acrocalanmus gibber, Bestiolina amoyensis, Paracalanus parvus, Acartia danae, Mesocyclops leuckarti, Noctiluca scientillans, Penilla avirostris, and Lucifer penicilliger. The annual average Shannon-Wiener diversity index, Margalef diversity index, Pielou evenness index were 1.75, 1.83, and 0.74, respectively. The effects of environmental factors on the zooplankton community were studied by R and canonical correspondence analysis (CCA). According to Pearson correlation analysis and canonical correspondence analysis, the most important environmental factors influencing the changes of zooplankton species composition, abundance and distribution were water temperature, salinity, and pH in the whole year.

Development of a 19-plex short tandem repeat typing system for individual identification and parentage testing of horses (Equus caballus)

Individual identification of horses for pedigree verification and registration is important for the sustainable development of the horse industry. Horse individual identification and parentage tests commonly use the 17 short tandem repeats (STRs) recommended by the International Society for Animal Genetics (ISAG) and the locus LEX33. While many multiplex STR typing systems have been established for the horse, a sex determining marker is usually absent, and none of them can simultaneously detect all 17 ISAG recommended loci and the locus LEX33. Here, we present a 19-plex STR typing system that contains the 17 ISAG recommend loci, the locus LEX33 and amelogenin as sex determining loci. The results of our sensitivity, species specificity, stutter analysis and population data analysis, indicate that this system is a specific, sensitive, and robust tool for the identification of individuals, parentage testing and genetic research in the horse.