Suppression of microRNA-320 Induces Cerebral Protection Against Ischemia/Reperfusion Injury by Targeting HMGB1/NF-kappaB Axis

MicroRNAs have been shown to potentially function in cerebral ischemia/reperfusion (IR) injury. This study aimed to examine the expression of microRNA-320 (miR-320) in cerebral IR injury and its involvement in cerebral mitochondrial function, oxidative stress, and inflammatory responses by targeting the HMGB1/NF-kappaB axis. Sprague-Dawley rats were subjected to middle cerebral artery occlusion to simulate cerebral IR injury. The cerebral expression of miR-320 was assessed using qRT-PCR. Neurological function, cerebral infarct volume, mitochondrial function, oxidative stress, and inflammatory cytokines were evaluated using relevant methods, including staining, fluorometry, and ELISA. HMGB1 expression was analyzed through Western blotting. The levels of miR-320, HMGB1, neurological deficits, and cerebral infarction were significantly higher after IR induction. Intracerebral overexpression of miR-320 resulted in substantial neurological deficits, increased infarct volume, elevated levels of 8-isoprostane, NF-kappaBp65, TNF-alpha, IL-1beta, ICAM-1, VCAM-1, and HMGB1 expression. It also promoted the loss of mitochondrial membrane potential and ROS levels while reducing MnSOD and GSH levels. Downregulation of miR-320 and inhibition of HMGB1 activity significantly reversed the outcomes of cerebral IR injury. MiR-320 plays a negative role in regulating cerebral inflammatory/oxidative reactions induced by IR injury by enhancing HMGB1 activity and modulating mitochondrial function.

Osteoporosis is associated with depression among older adults: a nationwide population-based study in the USA from 2005 to 2020

OBJECTIVES

The global prevalence of osteoporosis is rising, yet it is unclear whether people with osteoporosis have a higher risk of depression than those without osteoporosis.

STUDY DESIGN

A cross-sectional study.

METHODS

We used nationally representative data from the US National Health and Nutrition Examination Survey (NHANES) in 2005-2006, 2007-2008, 2009-2010, 2013-2014, and 2017-2020. The diagnosis of osteoporosis was based on the bone mineral density of the femoral neck measured by dual-energy X-ray absorptiometry. Depression was assessed by the Patient Health Questionnaire-9 (PHQ-9), with a score ≥5 as depressive symptoms and a score ≥10 as probable depression. We used logistic regression models to evaluate the association between osteoporosis and depressive symptoms and probable depression.

RESULTS

We included 11,603 adults (aged 50 years and older, 52.3% male) and observed 5.2% of them had osteoporosis. 31.9% of these osteoporotic people had depressive symptoms, and 10.0% had probable depression. Compared to participants without osteoporosis, those with osteoporosis were 1.73 times more likely to experience depressive symptoms (odds ratio [OR] = 1.73, 95% confidence interval [CI] 1.20-2.50) and 1.91 times more likely to experience probable depression (OR = 1.91, 95% CI 1.02-3.59), after adjusting for sex, age, race/ethnicity, education, marital status, family income, body mass index, smoking, physical activity, and alcohol abuse. Moderate-to-vigorous activities mediated the associations between osteoporosis and depression and depressive symptoms.

CONCLUSIONS

Osteoporosis is an independent risk factor for depression. This study highlights the need to evaluate the mental well-being of patients with osteoporosis in clinical and primary health care.

Essential omega-3 fatty acids are depleted in sea ice and pelagic algae of the Central Arctic Ocean

Microalgae are the main source of the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), essential for the healthy development of most marine and terrestrial fauna including humans. Inverse correlations of algal EPA and DHA proportions (% of total fatty acids) with temperature have led to suggestions of a warming-induced decline in the global production of these biomolecules and an enhanced importance of high latitude organisms for their provision. The cold Arctic Ocean is a potential hotspot of EPA and DHA production, but consequences of global warming are unknown. Here, we combine a full-seasonal EPA and DHA dataset from the Central Arctic Ocean (CAO), with results from 13 previous field studies and 32 cultured algal strains to examine five potential climate change effects; ice algae loss, community shifts, increase in light, nutrients, and temperature. The algal EPA and DHA proportions were lower in the ice-covered CAO than in warmer peripheral shelf seas, which indicates that the paradigm of an inverse correlation of EPA and DHA proportions with temperature may not hold in the Arctic. We found no systematic differences in the summed EPA and DHA proportions of sea ice versus pelagic algae, and in diatoms versus non-diatoms. Overall, the algal EPA and DHA proportions varied up to four-fold seasonally and 10-fold regionally, pointing to strong light and nutrient limitations in the CAO. Where these limitations ease in a warming Arctic, EPA and DHA proportions are likely to increase alongside increasing primary production, with nutritional benefits for a non-ice-associated food web.

Impacts of Atlantic water intrusion on interannual variability of the phytoplankton community structure in the summer season of Kongsfjorden, Svalbard under rapid Arctic change

Atlantification, known as impacts of high-latitude Atlantic water inflows on the Arctic Ocean has strengthened owing to climate change, corresponding to the rapid ice retreat in the Arctic. The relationship between phytoplankton and environmental changes in the Arctic on the interannual scale is unclear because of the lack of long-time series data. In this study, we discuss the ecological response to Atlantic water intrusion in the Kongsfjorden,Svalbard. We measured chlorophyll a and photosynthesis pigments for the water column samples from a fixed section along the Kongsfjorden to study the response of phytoplankton biomass and communities to Atlantic water intrusion in the summer season from 2007 to 2018. The results showed that dinoflagellates, prasinophytes, cryptophytes, and chlorophytes consistently accounted for over 50% of the total biomass, with the distinct annual variation of chlorophyll a. Bioavailable nitrogen was the main limiting factor on phytoplankton growth in the study area, as inferred by its concentration and nutrients ratios. The relationship between phytoplankton and water mass analysis suggested that the intrusion of Atlantic water in Kongsfjorden may cause interannual variability of the phytoplankton biomass and community structure by influencing the nutrient supply and water stratification in the fjord region. Our study provides insights into the ongoing impact of Atlantification on the phytoplankton community in the Arctic fjord.

Safety and Efficacy of Hypofractionated Radiotherapy Combined with Tyrosine Kinase Inhibitors in Patients with Lung Metastases after Liver Transplantation for Hepatocellular Carcinoma

PURPOSE/OBJECTIVE(S)

We evaluated the safety and efficacy of hypofractionated radiotherapy (HFRT) combined with tyrosine kinase inhibitors (TKIs) in patients with pulmonary metastases after orthotopic liver transplantation (OLT) for hepatocellular carcinoma (HCC).

MATERIALS/METHODS

Twenty-five patients with lung metastases after OLT for HCC who underwent HFRT using helical tomotherapy concomitantly with TKIs (sorafenib or lenvatinib) were retrospectively. The primary endpoint was progression-free survival (PFS). The secondary endpoints were overall survival (OS), local control rate (LCR), objective response rate (ORR), and treatment-related side effects.

RESULTS

The median follow-up time was 35.5 months, with a median interval from OLT to lung metastasis of 15.3 months. The median PFS and OS were 9.9 and 32.7 months, respectively. The 1-, 2-, and 3-year PFS and OS rates were 36.0%, 16.0%, and 12.0%, and 84.0%, 52.0%, and 20.0%, respectively. The LCR of pulmonary metastases at 1 year was 100%, whereas the two-year LCR was 76.9%. The 1- and 2- year ORRs were 95.2% and 69.2%, respectively, with no grade > 2 adverse events. Radiation pneumonitis was observed in 17 patients (68.0%). Grade 1 pneumonitis occurred in 15 patients (60.0%), and grade 2 pneumonitis occurred in 2 patients (8.0%).

CONCLUSION

The combination therapy of HFRT with TKIs is a feasible, safe, and promising approach in the treatment of pulmonary metastases for HCC after OLT.

Stereotactic Body Radiotherapy Combined with Sintilimab in Patients with Recurrent or Oligometastatic Hepatocellular Carcinoma: A Phase II Clinical Trial

PURPOSE/OBJECTIVE(S)

The anti-tumor activity and tolerability of stereotactic body radiotherapy (SBRT) and PD-1 inhibitors have been illustrated in retrospective studies, but the results vary across a broad range. This study aimed to assess the clinical efficacy of SBRT combined with sintilimab in patients with recurrent or oligometastatic hepatocellular carcinoma (HCC).

MATERIALS/METHODS

This trial involved patients with recurrent or oligometastatic HCC intravenously treated with SBRT plus sintilimab every 3 weeks for 12 months or until disease progression. The primary endpoint was progression-free survival (PFS).

RESULTS

Twenty-five patients were enrolled from August 14, 2019, to August 23, 2021. The median treatment duration was 10.2 months. SBRT was delivered at a median dose of 54 in six fractions. The median follow-up time was 21.9 months, and 32 targeted lesions among 25 patients were evaluated for treatment response according to the Response Evaluation Criteria in Solid Tumors version 1.1. The median PFS was 19.7 months, with PFS rates of 68% and 45.3% at 12 and 24 months, respectively. The median overall survival (OS) was not reached, with OS rates of 91.5% and 83.2% at 12 and 24 months, respectively. The 1- and 2-year local control rate were 100% and 90.9%, respectively. The confirmed objective response rate and disease control rate was 96%, and 96%, respectively. Most adverse events were graded as 1 or 2, and grade 3 adverse events were observed in three patients.

CONCLUSION

SBRT plus sintilimab is an effective, well-tolerated treatment regimen for patients with recurrent or oligometastatic HCC.

Biogeochemical and physical controls on ammonium accumulation on the Chukchi shelf, western Arctic Ocean

Spatial variability of ammonium concentrations along repeat transects were examined on the Chukchi shelf during 2012-2018. Two distinct near-bottom high ammonium pools (>1 μmol/kg) near 67.5°N and 72.5°N of the transects were identified in all years. The accumulation of ammonium in the regions is driven primarily by a combination of biogeochemical processes (e.g., dynamic bacterial remineralization of organic matter) and physical controls (e.g., strong density-contrast barrier limits upward mixing of ammonium). The ammonium pool on the shelf may became larger in the expectation of the stronger bacterial remineralization following elevate primary production, and may have potential impact on the structure and productivity of ecosystem on the Chukchi shelf.

Concentrations and controls of dissolved inorganic carbon in Arctic summer sea ice and adjacent surface seawaters

The carbonate chemistry of sea ice plays a critical role in global ocean carbon cycles, particularly in polar regions which are subject to significant climate change-induced sea ice variation. However, less is known about the interaction of carbonate system between sea ice and its adjacent seawaters due to sparse sampling and disparities in reported results. Here we provide an insight into this issue by collecting and measuring dissolved inorganic carbon (DIC) and associated environmental parameters in Arctic sea ice during a cruise in the summer of 2014. Our observations show that DIC in Arctic summer sea ice has a mean concentration of 463.3 ± 213.0 μmol/kg and appears to be controlled mainly by the fraction of brine water in the ice. The low Chl a and nutrients content in sea ice indicate minor contribution of biological uptake to sea-ice DIC in the western Arctic Ocean. The DIC concentration in surface water (<100 m depth) decreased from a mean of 2108.3 ± 45.4 μmol/kg in 1994 to a mean of 2052.4 ± 98.6 μmol/kg in 2014, due to the enhanced sea ice melting that dilutes the DIC concentrations of surrounding seawaters.

Overexpression of Circ_0005585 Alleviates Cerebral Ischemia Reperfusion Injury via Targeting MiR-16-5p

Circular RNAs are implicated in the pathogenesis of ischemic stroke. In this work, we explored the modulation and potential mechanisms of action of circ_0005585 in ischemic stroke. Expression of circ_0005585 and miR-16-5p was assessed by quantitative real-time reverse transcription PCR. Ischemic stroke was modeled in mice by middle cerebral artery occlusion (MCAO). The infarct volume was assessed by triphenyl tetrazolium chloride staining. Neurological deficits were evaluated according to Neurological Severity Score. The permeability of the blood-brain barrier was assessed by Evan's blue leakage and brain water content. Apoptosis in brain tissues was measured by the TUNEL test. Relative expression of apoptosis-related proteins was evaluated by Western blotting. The direct interaction between circ_0005585 and miR-16-5p was verified by dual-luciferase reporter assay. The expression of circ_0005585 was lower in mice with MCAO. Lentivirus-mediated overexpression of circ_0005585 ameliorated the neurological deficits and decreased the infarction volume in MCAO mice. The brain water content and Evan's blue leakage through the blood-brain barrier were reduced. In addition, overexpression of circ_0005585 inhibited apoptosis in the cerebral tissues. Our results revealed direct interaction between circ_0005585 and miR-16-5p. Hence, circ_0005585 protects mouse brain during ischemic stroke by targeting miR-16-5p, which uncovers the pathogenesis of this pathology and opens new vitas for its therapy.

Predictive model for deep venous thrombosis caused by closed lower limb fracture after thromboprophylactic treatment

OBJECTIVE

Currently, there are still no convincing clinical models predicting closed lower extremity fracture-associated deep vein thrombosis in patients treated through thromboprophylactic methods. We aimed at using two retrospective cohorts to develop and externally verify a clinical prediction model for deep vein thrombosis in patients treated with anticoagulants after suffering closed lower extremity fractures.

PATIENTS AND METHODS

We evaluated the patients' pre- and post-operatively, to accurately determine the predictive power of the biomarkers and clinical risk factors. Two retrospective cohorts were used for the development and external verification of a pre-operative clinical prediction model (development: n = 2,253; verification: n = 833) and post-operative clinical prediction model (development: n = 1,422; verification: n = 449), respectively.

RESULTS

The C-indices were used to show the predicted incidence of objective thrombosis at the pre- and post-operative stage, which were then compared with the observed incidence of thrombosis in both cohorts. Biomarkers and clinical indicators were included in pre- and post-operative nomograms, which were adequately calibrated in both cohorts. The cross-validated C-indices of the pre- and post-operative clinical prediction models in the verification cohort were 0.706 (95% Cl, 0.67-0.74) and 0.875 (95% Cl, 0.84-0.91), respectively.

CONCLUSIONS

We present our findings of novel pre- and post-operative nomograms for the prediction of deep venous thrombosis in patients who received thromboprophylaxis after suffering closed lower extremity fractures.

Climate change drives rapid decadal acidification in the Arctic Ocean from 1994 to 2020

The Arctic Ocean has experienced rapid warming and sea ice loss in recent decades, becoming the first open-ocean basin to experience widespread aragonite undersaturation [saturation state of aragonite (Ω_arag) < 1]. However, its trend toward long-term ocean acidification and the underlying mechanisms remain undocumented. Here, we report rapid acidification there, with rates three to four times higher than in other ocean basins, and attribute it to changing sea ice coverage on a decadal time scale. Sea ice melt exposes seawater to the atmosphere and promotes rapid uptake of atmospheric carbon dioxide, lowering its alkalinity and buffer capacity and thus leading to sharp declines in pH and Ω_arag. We predict a further decrease in pH, particularly at higher latitudes where sea ice retreat is active, whereas Arctic warming may counteract decreases in Ω_arag in the future.

[The influence of sacroiliac joint reduction quality on the clinical effect of bionic reduction and internal fixation for pelvic ring injury]

Objective: To examine the influence of sacroiliac joint reduction quality on the clinical effect of bionic reduction and internal fixation for pelvic ring injury. Methods: From January 2014 to February 2019,the clinical data of 78 patients diagnosed with pelvic ring injury involving sacroiliac joints and treated with bionic reduction and internal fixation at Honghui Hospital Affiliated to Medical College of Xi'an Jiaotong University were retrospectively analyzed.There were 48 males and 30 females,aged (48.3±8.3)years (range:28 to 68 years).After bionic reduction and internal fixation,the patients were grouped according to the maximum displacement distance (d) of sacroiliac joint residual on the damaged side measured by CT examination. Patients with d≤5 mm were included in anatomical bionic reduction group,and patients with d>5 mm were included in non-anatomical bionic reduction group.In non-anatomical bionic reduction group,according to the direction of residual displacement,the patients were divided into separation displacement group and anterior-posterior displacement group. The X-ray examination was performed immediately and at the last follow-up after operation.If sacroiliac joint was relocated,or internal plant loosening,displacement,fracture and re-displacement of fracture,it was defined as internal fixation failure.Majeed pelvic fracture scoring system was used to evaluate the postoperative functional status of the two groups,and visual analogue scale (VAS) was used to evaluate the postoperative pain.Comparison between groups was performed by completely random design ANOVA,χ² test,Fisher's exact test,Mann-Whitney U and Kruskal-Wallis H test. Results: According to the CT examination,28 cases were included in anatomical bionic reduction group,and 50 cases were included in non-anatomical bionic reduction group.In non-anatomical bionic reduction group,27 cases were divided into separation displacement group and 23 cases were in anterior-posterior displacement group.There was no significant difference in general data among anatomical bionic reduction group,separation displacement group and anterior-posterior displacement group (P>0.05). The follow-up time was (37.8±6.6) months (range:25 to 51 months). At the last follow up,the excellent and good rate of Majeed score in anatomical bionic reduction group was 96.4%(27/28),which was better than that in separation displacement group(74.1%(20/27)) and anterior-posterior displacement group (30.4%(7/23)),the difference was statistically significant (Z=-6.479,P<0.01;Z=-6.256,P<0.01); and the good rate of the separation displacement group was better than that of the anterior-posterior displacement group(Z=-3.607,P<0.01).The VAS of anatomical bionic reduction group (17 cases with 0 point, 11 cases with 1 to 3 points) were lower than that of the displacement group (6 cases with 0 point,16 cases with 1 to 3 points,5 cases with 4 to 6 points) and anterior-posterior displacement group (3 cases with 0 point,7 cases with 1 to 3 points,13 cases with 4 to 6 points),the difference was statistically significant (Z=-3.515,P<0.01;Z=-3.506,P<0.01),and there was no difference between separation displacement group and anterior-posterior displacement group.Total of 8 cases of internal fixation failure occurred,and the failure rate of anatomical bionic reduction group (0,0/28) was lower than that of the separation displacement group (11.1%,3/27) and anterior-posterior displacement group (21.7%,5/23) (P=0.111,P=0.014),and there was no difference between separation displacement group and anterior-posterior displacement group(P=0.444). Conclusions: In the bionic reduction and internal fixation of pelvic fracture involving sacroiliac joint injury,the functional status,pain and internal fixation failure rate of patients with anatomical bionic reduction of sacroiliac joint are significantly better than those in the non-anatomical bionic reduction.The functional recovery of patients with separation displacement is better than that of the patients with anterior and posterior displacement.

Seasonal Water Mass Evolution and Non-Redfield Dynamics Enhance CO2 Uptake in the Chukchi Sea

The Chukchi Sea is an increasing CO₂ sink driven by rapid climate changes. Understanding the seasonal variation of air-sea CO₂ exchange and the underlying mechanisms of biogeochemical dynamics is important for predicting impacts of climate change on and feedbacks by the ocean. Here, we present a unique data set of underway sea surface partial pressure of CO₂ (pCO₂) and discrete samples of biogeochemical properties collected in five consecutive cruises in 2014 and examine the seasonal variations in air-sea CO₂ flux and net community production (NCP). We found that thermal and non-thermal effects have different impacts on sea surface pCO₂ and thus the air-sea CO₂ flux in different water masses. The Bering summer water combined with meltwater has a significantly greater atmospheric CO₂ uptake potential than that of the Alaskan Coastal Water in the southern Chukchi Sea in summer, due to stronger biological CO₂ removal and a weaker thermal effect. By analyzing the seasonal drawdown of dissolved inorganic carbon (DIC) and nutrients, we found that DIC-based NCP was higher than nitrate-based NCP by 66%-84% and attributable to partially decoupled C and N uptake because of a variable phytoplankton stoichiometry. A box model with a non-Redfield C:N uptake ratio can adequately reproduce observed pCO₂ and DIC, which reveals that, during the intensive growing season (late spring to early summer), 30%-46% CO₂ uptake in the Chukchi Sea was supported by a flexible stoichiometry of phytoplankton. These findings have important ramification for forecasting the responses of CO₂ uptake of the Chukchi ecosystem to climate change.

[Effects of high-flow nasal oxygen combined with early extubation on the incidence of respiratory adverse events during emergence from general anesthesia in children undergoing adenoid-tonsillectomy]

Objective: To investigate the effects of high-flow nasal oxygen (HFNO) combined with early extubation on the incidence of respiratory adverse events (RAE) during emergence from general anesthesia in children undergoing adenoid-tonsillectomy. Methods: From December 2021 to January 2022, 40 pediatric patients [21 males, 19 females, with a median age of 4 (4, 5) years] undergoing tonsillectomy and/or adenoidectomy in Eye & ENT Hospital of Fudan University were randomly divided into two groups: HFNO-assisted early extubation group (Group H, n=20) and conventional extubation group (Group C, n=20) by using a random number table. After entering the post-anesthesia care unit (PACU), the patients in group H received humidified and heated oxygen (flow rate: 25 L/min) through a nasal cannula until their consciousness regained. After patient's spontaneous breathing resumed for 10 min, the oral endotracheal tube was removed. Patients in group C did not receive HFNO. The oral endotracheal tube was removed after the patient's spontaneous breathing resumed for at least 10 min with signs of tube intolerance, or 20 min without signs of tube intolerance. During the PACU stay, the incidence of RAE, the incidence of cough, the application rate of intensive care strategy, the time to extubation, the duration of PACU stay, and vital signs at spontaneous breathing resuming and extubation in each group were recorded. Results: In Group H, the total incidence of RAE [30% (6/20) vs 65% (13/20), P=0.027], the incidence of cough [10% (2/10) vs 45% (9/20), P=0.031] and the application rate of intensive care strategy [20% (4/20) vs 55% (11/20), P=0.048] during PACU stay was significantly lower, compared with those of Group C. Likewise, the time to extubation was significantly shorter [(33.4±4.5) min vs (42.7±5.3) min, P<0.001]. However, there was no statistically significant difference in the duration of PACU stay, the vital signs at the time of spontaneous breathing resuming and extubation between the two groups (P>0.05), except that the end-tidal carbon dioxide partial pressure (P_ETCO₂) at the time of extubation in group H was significantly higher than group C [(52.9±9.4) mmHg vs (48.9±3.1) mmHg (1 mmHg=0.133 kPa), P<0.001]. Conclusion: HFNO combined with early extubation can significantly reduce the incidence of RAE in children undergoing adenoid-tonsillectomy during the emergence from general anesthesia.

[Sensitization characteristics of Juniperus chinensis pollen in Beijing area]

Objective: To investigate the sensitization characteristics of Juniperus chinensis pollen in patients with allergic rhinitis and/or allergic asthma in Beijing area, and to explore the characteristics of Juniper chinensis pollen sensitized population. Methods: Patients with suspected allergic rhinitis and/or asthma from January 2017 to December 2019 in the outpatient department of Allergy Department of Beijing Shijitan Hospital were selected in this study. Skin prick test (SPT) was performed with Juniper chinensis pollen allergen reagent to compare different age and disease allergen distribution, and to observe the sensitization characteristics of its population. All of the analyses were performed using SAS software version 9.4. Results: A total of 8 380 patients were enrolled in the end. The total positive rate of Juniper chinensis pollen SPT reached 49.92% (4 183/8 380). The positive rate of Juniper chinensis pollen SPT was highest in the 10-14 age group, reaching 60.99% (283/464). Compared with other age groups, there was a statistical difference (χ²=266.77, P<0.01). The SPT positive rate of patients aged less than 10 years increased with the increase of age, while the SPT positive rate of patients aged over 40 years decreased with the increase of age. Single Juniper chinensis pollen was less allergenic, accounting for about 25.05% (1 048/4 183), and the patients' age was (35.21±12.39) years. Regardless of single Juniper chinensis pollen or other pollen allergies, allergic rhinitis was the main disease. Among the patients with SPT positive Juniper chinensis pollen combined with other inhaled pollen allergens, willow pollen accounted for the first (74.99%). The positive rate of Juniper chinensis pollen was the highest in patients with single allergic rhinitis, accounting for 52.05% (3 797/7 295), and the rate in patients with single allergic asthma was the lowest, accounting for 17.49% (53/303), with statistically difference (χ²=138.99, P<0.01). Conclusions: Juniper chinensis pollen is highly sensitized in patients with allergic rhinitis and/or allergic asthma in Beijing . The positive rate of SPT is highest among 10-14 age group, most of which showed strong positive reaction, and allergic rhinitis is more common in Juniper chinensis pollen sensitization diseases.

Longitudinal investigations of anatomical and morphological development of the gastrointestinal tract in goats from colostrum to postweaning

The digestive tract development in goat kids around weaning is vital to the establishment of digestion and absorption function, growth, and health of adults. The objective was to explore the effects of age and solid feed on the anatomical and morphological development of the gastrointestinal tract of Laiwu Black goat kids. Forty-eight female Laiwu Black goats at 8 ages (1, 7, 14, 28, 42, 56, 70, and 84 d; 6 goats per group) were selected and killed for anatomical and morphological analysis. The goats experienced the following 4 diet phases: maternal colostrum (MC; d 1, d 7), maternal milk (MM; d 14, d 28), maternal milk plus solid diet (MMSD; d 42, d 56) and only solid diet (OSD; d 70, d 84). The body and carcass weights were not significantly changed during MC and MM phases but changed during the MMSD phase. The absolute growth of body and carcass weights were higher in the MMSD phase than in MM phase. In addition, the dressing percentage was the highest in the MMSD phase. The body size indices evolved progressively and increased over time. The percentage of internal and external organs to body weight decreased over time, whereas the percentage to complex stomach percentage increased. The rumen and omasum weight experienced synchronous absolute growth over time, especially in the OSD phase. In contrast, the absolute growth of the reticulum and abomasum was the highest in MMSD and MC phases, respectively. After weaning, the goats showed the highest papillae height, lamina propria, muscle layer thickness, and epithelial thickness. The OSD phase showed the highest colonic mucosa thickness, ileal villus height, and ileal muscle layer thickness. The crypt depth was higher in the MMSD phase than in the MM phase. Moreover, the crypt depth and muscle layer thickness of jejunum increased over time. Furthermore, duodenal crypt depth, muscle layer thickness, and epithelial thickness increased in the OSD phase compared with other stages. In conclusion, the histological investigation supports the improvement of the morphological development of the digestive tract and the growth performance in the solid feed phase. It is recommended to add solid food as early as 4 wk old.

Nitrogen removal through sediment denitrification in the Yangtze Estuary and its adjacent East China Sea: A nitrate limited process during summertime

Nitrogen nutrient surplus is the main cause of a series of environmental problems in the Yangtze Estuary and its adjacent East China Sea (ECS). Denitrification plays an important role in controlling nitrate dynamics and fate in estuarine and coastal environments. We investigated the natural and potential rates of denitrification in the sediments of the Yangtze Estuary and ECS via slurry incubation experiments combined with acetylene inhibition techniques to reveal its contributions to total nitrogen reduction in this hypereutrophic continental shelf area. Key environmental factors, such as the sediment grain size, sediment extractable inorganic nitrogen (NH₄⁺, NO₃^- and NO₂^-), sediment organic carbon (SOC), total nitrogen (TN), isotopic compositions (δ¹³C and δ¹⁵N), etc., were also investigated to determine the main factors controlling the denitrification processes. The measured rates of denitrification ranged from 0.39 to 28.49 ng N g^-1·h^-1. The total nitrogen removed by denitrification in the study area was 3.7 × 10¹⁰ g during August. In total, at least 3.3% of the external inorganic nitrogen transported annually into the estuary could be removed by the denitrification processes in the study area. The sediment denitrification rates correlated significantly with the extractable ammonium and δ¹⁵N values of surface sediments, indicating that coupled nitrification-denitrification processes may play an important role in nitrogen removal. Almost undetectable levels of nitrate in the sediment further revealed that nitrate supply, regardless of diffusion from the overlying water or production by sediment nitrification processes, is the bottleneck for denitrification.

Mechanism of curcumin against myocardial ischaemia-reperfusion injury based on the P13K/Akt/mTOR signalling pathway

OBJECTIVE

To investigate the pharmacodynamic mechanism of curcumin against myocardial ischaemia-reperfusion injury by regulating the phosphatidylinositol-3 kinase (PI3K)/protein kinase B (AKT)/rapamycin target protein (mTOR) signalling pathway.

MATERIALS AND METHODS

The left anterior descending coronary artery was ligated for 30 min and reperfused for 3 h to establish an ischaemia-reperfusion injury model. The electrocardiogram (ECG) detection of rats was performed, and the degree of myocardial infarction was determined by 2,3,5-triphenyltetrazolium chloride staining. The expression levels of serum creatine kinase isoenzyme (CK), lactate dehydrogenase (LDH), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), malondialdehyde (MDA), nitric oxide (NO) and other related indicators were detected. The protein expressions of mTOR, phosphorylated (p)-mTOR, AKT and p-AKT were detected by Western blotting, whereas the expressions of Bcl-2 and Bax were detected by real-time polymerase chain reaction.

RESULTS

The results showed that compared with the model group, curcumin could improve the ECG findings, reduce the scope of myocardial infarction, reduce the expression levels of CK-MB, LDH, AST, MDA, NO and increase those of SOD and GSH. Curcumin can also down-regulate the expression of Bax and up-regulate the protein levels of Bcl2, p-mTOR and p-AKT (p < 0.05 or p < 0.01).

CONCLUSIONS

This study shows that curcumin has a significant protective effect on myocardial ischaemia-reperfusion, and its mechanism may be related to the activation of PI3K/AKT/mTOR signalling pathway and inhibition of inflammation, apoptosis and oxidative stress.

[Incidence and trend of severe postpartum hemorrhage between 2016 and 2019 in China]

Objective: To investigate the incidence and trend of severe postpartum hemorrhage (sPPH) in China, and to provide basic data for the development and evaluation of sPPH prevention and control strategy. Methods: Obstetric data was extracted from annual national representative sampling surveys based on the National Clinical Improvement System. From 2016 to 2019, 2 978, 3 400, 4 576 and 4 594 maternity hospitals with sPPH cases were included for statistics. The annual incidence of sPPH was calculated according to province and type of medical institutions and generalized linear model was emplyed to identify the determinants affecting sPPH incidence. Results: In China, sPPH incidence increased from 0.62% in 2016 to 0.93% in 2018, and was 0.92% in 2019. Eighteen provinces had an inverted U-shaped trend of sPPH over time and most of them had the highest incidence in 2018; ten provinces had an upward trend of sPPH and 3 provinces had a U-shaped trend. In 2019, the top five provinces with the highest sPPH incidence were Yunnan (1.88%), Beijing (1.45%), Jiangsu (1.31%), Guizhou (1.26%), and Ningxia Hui Autonomous Region (1.22%); the top five provinces with the lowest incidence were Henan (0.55%), Jiangxi (0.60%), Inner Mongolia Autonomous Region (0.64%), Liaoning (0.64%) and Gansu (0.69%). In 2019, the sPPH incidence in different types of medical institutions were as follows: tertiary public general hospital (1.15%), tertiary public specialized hospital (1.02%), secondary public general hospital (0.81%), private hospital (0.61%) and secondary public specialized hospital (0.58%). sPPH incidence was positively associated with proportion of twin pregnancies, macrosomia, primipara, and puerpera aged ≥35 years in maternity hospitals (P<0.05). Conclusions: sPPH incidence generally showes an increasing trend from 2016 and is stable at a high level in recent two years in China. It is warranted to further strengthen the monitoring of postpartum hemorrhage, and improve the capability of hierarchical management and treatment in maternity institutions and regions, in order to reduce sPPH incidence and maternal mortality.