Subsurface hydrological connectivity controls nitrate export flux in a hilly catchment

Subsurface runoff represents the main pathway of nitrate transport in hilly catchments. The magnitude of nitrate export from a source area is closely related to subsurface hydrological connectivity, which refers to the linkage of separate regions of a catchment via subsurface runoff. However, understanding of how subsurface hydrological connectivity regulates catchment nitrate export remains insufficient. This study conducted high-frequency monitoring of shallow groundwater in a hilly catchment over 17 months. Subsurface hydrological connectivity of the catchment over 38 rainfall events was analyzed by combining topography-based upscaling of shallow groundwater and graph theory. Moreover, cross-correlation analysis was used to evaluate the time-series similarity between subsurface hydrological connectivity and nitrate flux during rainfall events. The results showed that the maximum subsurface hydrological connectivity during 32 out of 38 rainfall events was below 0.5. Although subsurface flow paths (i.e., the pathways of lateral subsurface runoff) exhibited clear dynamic extension and contraction during rainfall events, most areas in the catchment did not establish subsurface hydrological connectivity with the stream. The primary pattern of nitrate export was flushing (44.7%), followed by dilution (34.2%), and chemostatic behavior (21.1%). A threshold relationship between subsurface hydrological connectivity and nitrate flux was identified, with nitrate flux rapidly increasing after the subsurface connectivity strength exceeded 0.121. Moreover, the median value of cross-correlation coefficients reached 0.67, which indicated subsurface hydrological connectivity exerts a strong control on nitrate flux. However, this control effect is not constant and it increases with rainfall amount and intensity as a power function. The results of this study provide comprehensive insights into the subsurface hydrological control of catchment nitrate export.

Multidisciplinary diagnosis and treatment nutritional support intervention for gastrointestinal tumor radiotherapy: Impact on nutrition and quality of life

BACKGROUND

Gastrointestinal tumors are a major cause of cancer-related deaths and have become a major public health problem. This study aims to provide a scientific basis for improving clinical treatment effects, quality of life, and prognosis of patients with gastrointestinal tumors.

AIM

To explore the clinical effect of the multidisciplinary diagnosis and treatment (MDT) nutrition intervention model on patients with gastrointestinal tumors.

METHODS

This was a case control study which included patients with gastrointestinal tumors who received radiotherapy at the Department of Oncology between January 2021 and January 2023. Using a random number table, 120 patients were randomly divided into MDT and control groups with 60 patients in each group. To analyze the effect of MDT on the nutritional status and quality of life of the patients, the nutritional status and quality of life scores of the patients were measured before and after the treatment.

RESULTS

Albumin (ALB), transferrin (TRF), hemoglobin (Hb), and total protein (TP) levels significantly decreased after the treatment. The control group had significantly lower ALB, TRF, Hb, and TP levels than the MDT group, and the differences in these levels between the two groups were statistically significant (P < 0.05). After the treatment, the MDT group had significantly more well-nourished patients than the control group (P < 0.05). The quality of life total score, somatic functioning, role functioning, and emotional functioning were higher in the MDT group than in the control group. By contrast, pain, fatigue, nausea, and vomiting scores were lower in the MDT group than in the control group (P < 0.05).

CONCLUSION

MDT nutritional intervention model effectively improves the nutritional status and quality of life of the patients. The study provides a rigorous theoretical basis for improving the prognosis of cancer patients. In the future, we intend to provide additional treatment methods for improving the quality of life of patients with cancer.

Identifying the Epitopes of Bacillus thuringiensis Cry2Aa Toxin Involved in Cadherin Interaction by a Monoclonal Antibody

Antibodies are a useful tool for assistance to map the binding epitopes in Bacillus thuringiensis Cry toxins and their receptors, and even determine how receptors promote toxicity. In this work, a monoclonal antibody (mAb-1D2) was produced by the hybridoma cell line raised against Cry2Aa toxins, with a half inhibition concentration (IC₅₀) of 9.16 μg/mL. The affinity constant of two recombinant toxin-binding fragments derived from Helicoverpa armigera and Plutella xylostella cadherin-like protein (HaCad-TBR or PxCad-TBR) to Cry2Aa toxin was measured to be 1.21 μM and 1.24 μM, respectively. Competitive ELISA showed that mAb-1D2 competed with HaCad-TBR or PxCad-TBR binding to Cry2Aa. Meanwhile, the toxicity of the Cry2Aa toxin to the H. armigera and P. xylostella larvae were greatly reduced when the toxin was mixed with mAb-1D2, which indicated that cadherin may play an important functional role in the toxicity of Cry2Aa. After transforming mAb-1D2 to a single-chain variable fragment (scFv), the hot spot residues of Cry2Aa with 1D2-scFv, PxCad-TBR, and HaCad-TBR were analyzed by molecular docking. It was demonstrated that the hot spot residues of Cry2Aa involving with 1D2-scFv interaction were mainly in Domain II, and some residues in Domain I. Moreover, mAb-1D2 and the two cadherin fragments shared the common hot spot residues on Cry2Aa, which could explain mAb-1D2 inhibited Cry2Aa binding with cadherin fragments. This monoclonal antibody could be a useful tool for identifying the binding epitopes between Cry2Aa and cadherin, and even assist to analyze the roles of cadherin in Cry2Aa toxicity.

[Reversal mechanism of hepatic fibrosis]

There is an increasing histological clinical evidence that both hepatic fibrosis and some degree of cirrhosis reversal can improve prognosis. Hepatic fibrosis involves a variety of cells and steps, and its reversal mechanism is also very complex, mainly including the reduction of hepatocyte necrosis and regeneration, the apoptosis and inactivation of activated hepatic stellate cells, and the reversal of hepatic sinusoidal endothelial cells and microvessels, restorative hepatic macrophages polarization and cell-to-cell interactions. Furthermore, the biochemical basis for reversal of hepatic fibrosis is decreased expression of matrix metalloproteinase inhibitors, up-regulation of matrix metalloproteinase activity, and increased degradation of extracellular matrix. However, at present, there are few studies on the clinicopathological mechanism of liver fibrosis reversal, and the key target groups of different etiologies with different degrees are still unclear, and the corresponding translational application research is lacking. Therefore, an in-depth and systematic understanding of the characteristics and mechanisms of hepatic fibrosis reversal can not only enrich the understanding of the natural history of hepatic fibrosis and cirrhosis, but also provide reference for the development and clinical application of anti-hepatic fibrotic drugs.

ASPM facilitates colorectal cancer cells migration and invasion by enhancing β-catenin expression and nuclear translocation

Increased abnormal spindle-like microcephaly (ASPM) expression has been linked to clinical stage and poor prognosis in cancers, but the molecular mechanisms by which ASPM promotes cell metastasis in colorectal cancer (CRC) has not been identified. This study showed that the abilities of cell migration, invasion, and epithelial-mesenchymal transition (EMT) were attenuated in ASPM-deficient CRC cell lines. Furthermore, we reported that attenuation of ASPM expression inhibited CRC cell metastasis in vivo. Additionally, the expression of ASPM was positively correlated with β-catenin level in CRC tissues. Mechanistically, ASPM can upregulate β-catenin transcription by stimulating the β-catenin promoter and enhancing the nuclear translocation of β-catenin in CRC cells, which leads to the activation of the Wnt/β-catenin pathway. Finally, we showed that ASPM effectively induced CRC cell migration and invasion in a β-catenin-dependent manner.

Caged structural water molecules emit tunable brighter colors by topological excitation

Intrinsically, free water molecules are a colourless liquid. If it is colourful, why and how does it emit the bright colours? We provided direct evidence that when water was trapped into the sub-nanospace of zeolites, the structural water molecules (SWs) exhibited strong tunable photoluminescence (PL) emissions from blue to red colours with unprecedented ultra-long lifetimes up to the second scale at liquid nitrogen temperature. Further controlled experiments and combined characterizations by time-resolved steady-state and ultra-fast femtosecond (fs) transient optical spectroscopy showed that the singly adsorbed hydrated hydroxide complex {OH^-·H₂O} as SWs in the confined nanocavity is the true emitter centre, whose PL efficiency strongly depends on the type and stability of the SWs, which is dominated by H-bond interactions, such as the solvent effect, pH value and operating temperature. The emission of SWs exhibits the characteristic of topological excitations (TAs) due to the many-body quantum electron correlations in confined nanocavities, which differs from the local excitation of organic chromophores. Our model not only elucidates the origin of the PL of metal nanoclusters (NCs), but also provides a completely new insight to understand the nature of heterogeneous catalysis and interface bonding (or state) at the molecule level, beyond the metal-centred d band theory.

[The relationship between elevated antiphospholipid antibodies and thrombosis in hospitalized patients]

Objective: Assess the relationship between elevated antiphospholipid antibodies and thrombosis in hospitalized patients. Methods: Case control study. A total of 385 patients (149 males and 236 females, aged from 1 to 105 years, with a median age of 37 years) who were hospitalized in Peking University First Hospital from January 2015 to December 2019 and tested positive for any one of the anti-phospholipid antibodies were included in the study. All subjects were divided into thrombotic group and non-thrombotic group according to whether thrombus was detected by imaging examination during hospitalization. In thrombosis group, there were 66 males and 36 females, aged from 3 to 105 years, with a median age of 58 years. In non-thrombosis group, there were 83 males and 200 females, aged from 1 to 94 years, with a median age of 31 years. Clinical data and laboratory data of patients were recorded. ACL-IgM/IgG and anti-β2GPI-IgM/IgG were detected by ELISA and LA was detected by dRVVT and SCT on automatic coagulation analyzer. The rates of age, gender, smoking, obesity, hypertension, hyperlipidemia, diabetes and the median level of antiphospholipid antibodies were compared between two groups. Logistic multivariate regression analysis was used to determine the risk factors for thrombotic events. The mid-to-high titer value of aCL was established by the χ²-trend test and verified by logistic regression. Results: The median age (58 years) and the rates of male (64.7%), smoking (16.7%), hypertension (63.7%) and diabetes (28.4%) in thrombus group were significantly higher than those in non-thrombus group (Z=7.685, χ²=38.077, 16.312, 37.769, 24.749 respectively; P<0.01). The positive rate of anti-β2GPI-IgG and dRVVT in thrombosis group (11.8% and 78.4%) was significantly higher than that in non-thrombosis group (5.3% and 60.1%), as well as the median level of dRVVT (1.29 RU/ml vs 1.23 RU/ml) (χ²=3.864 and 10.309, Z=3.539; P<0.05). The median level of aCL-IgM was higher in non-thrombosis group (2.3 MPL vs 2.0 MPL). The positive rate of aCL-IgG was slightly higher in thrombosis group (18.6% vs 10.6%). Logistic regression analysis showed that men, hypertension, diabetes, advanced age, elevated dRVVT, and elevated anti-β2GPI-IgG are risk factors for thrombosis. Taking 36 GPL as the medium-to-high titer value of aCL-IgG, the risk of thrombosis increased by 2.45 times. Conclusions: In the anti-phospholipid antibody profile, LA detected by dRVVT method, anti-β2GPI-IgG and aCL-IgG may be valuable laboratory indicators for inpatient thrombotic events. The mid-to-high titer value of aCL-IgG is set at 36 GPL to distinguish the risk of thrombosis.

Surface electronic states mediate concerted electron and proton transfer at metal nanoscale interfaces for catalytic hydride reduction of -NO2 to -NH2

Concerted electron and proton transfer is a key step for the reversible conversion of molecular hydrogen in both heterogeneous nanocatalysis and metalloenzyme catalysis. However, its activation mechanism involving electron and proton transfer kinetics remains elusive. With the most widely used catalytic hydride reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) as a model reaction, we evaluate the catalytic activity of noble metal nanoparticles (NPs) trapped in porous silica in aqueous NaBH4 solution. By virtue of a novel combination of catalyst design, reaction kinetics, isotope labeling, and multiple spectroscopic techniques, the real catalytic site for the conversion of -NO2 to -NH2 is identified to be the water-hydroxyl transition metal complex, which could further react with NaBH4 to form a new triangular configuration metal complex of H3B-water-hydroxyl with dynamic features. It yields an ensemble of surface electronic states (SESs) though space overlapping of p orbitals of one B and several O atoms (including the O atoms of 4-NP), which could act as an alternative channel for concerted electron and proton transfer. This work highlights the critical role of the conceptual SESs model in heterogeneous catalysis to tune the chemical reactivity and also sheds light on the intricate working of the [FeFe]-hydrogenases.

Guizhi Fuling Wan, Chinese Herbal Medicine, Ameliorates Insulin Sensitivity in PCOS Model Rats With Insulin Resistance via Remodeling Intestinal Homeostasis

Polycystic ovary syndrome (PCOS) is a common endocrine disease with reproductive dysfunction and metabolic disorder in women of childbearing age. Gastrointestinal microbiome contributes to PCOS through mediating insulin resistance. Guizhi Fuling Wan, Chinese herbal medicine, can treat PCOS with insulin resistance (PCOS-IR), but the underlying mechanism is not clear. The aim of this study was to characterize the exact mechanism of Guizhi Fuling Wan action and whether it is related to the regulation of intestinal flora structure. We induced PCOS-IR rat model by means of letrozole sodium carboxymethyl cellulose (CMC-na) solution combined with high-fat emulsion administration and randomly divided it into blank control group (K), model control group (M), low dose of Guizhi Fuling Wan group (D), middle dose of Guizhi Fuling Wan group (Z), high dose of Guizhi Fuling Wan group (G) and positive drug (Metformin) control group (Y). After 36 days of modeling and treatment, serum and stool samples from all rats were collected for a follow-up analysis. The data display that, compared with K group, elevated testosterone and HOMA-IR, turbulent estrous cycles and polycystic ovaries in M group, indicating the PCOS-IR rat model is successfully established. Increased fasting insulin is associated with higher inflammation(plasma TNF-α, IL-6, and HS-CPR concentration were determined) in M group, and the altered intestinal flora (compared with the K group, in M group the relative abundance of Alloprevotella was decreased significantly, while the relative abundance of Lachnospiraceae UCG-008, Lachnospiraceae NK4A136, Lactobacillus, Ruminiclostridium 9, and Ruminococcaceae UCG-003 was increased significantly) induced the secretion of inflammatory markers. On the other hand, Guizhi Fuling Wan can alleviate inflammation, improve insulin resistence: Lower inflammation decreased fasting insulin can be seen in G group compared with M group, this effect is related to the regulating effect of Guizhi Fuling Wan on intestinal flora (in G group, the relative abundance of Alloprevotella, Ruminococcaceae UCG-003, and Lachnospiraceae UCG-008 was increased significantly, compared with M group). This research demonstrates Guizhi Fuling Wan improve insulin resistance in polycystic ovary syndrome with the underlying mechanism of regulating intestinal flora to control inflammation. It would be useful to promote the therapeutic effect of Guizhi Fuling Wan on PCOS-IR.

[Clinical observation of autologous simple limbal epithelial transplantation for unilateral limbal stem cell deficiency]

Objective: To discuss effect of autologous simple limbal epithelial transplantation (SLET) performed for unilateral limbal stem cell deficiency (LSCD). Methods: Retrospective case study. In this retrospective study, records of 7 patients (7 eyes) who had undergone autologous SLET for unilateral LSCD, with a minimum of 6 months of follow-up, were reviewed. Demographic details, etiology of LSCD, duration between ocular burn and SLET, prior surgery performed, presence or absence of symblepharon, pre-and post-operative visual acuity, and complications were noted. Results: Seven eyes of 7 patients underwent autologous SLET. With a follow-up of 6 months, a completely epithelialised and stable corneal surface was obtained in all recipient eyes. Visual acuity improved in all patients, while none of the eyes developed any complications. Conclusions: Autologous SLET is an effective and safe modality for treatment of unilateral LSCD. Clinical success rates and visual acuity improvement are equal to or better than those reported with earlier techniques. (Chin J Ophthalmol, 2019, 55:923-927).

Adaptive velocity-dependent proportional-integral controller for high-speed atomic force microscopy

High-speed atomic force microscopy (AFM) has been rapidly developed in recent years. To reduce the oscillation of the scanner, a single-tone sinusoidal wave is widely used as a scanning wave rather than a triangular wave in high-speed AFM. However, the sinusoidal wave is nonlinear, resulting in a nonconstant relative linear velocity between the sample and the tip while scanning in the x-direction. If a traditional proportional-integral controller is still used as a feedback controller in the z-direction, the control errors will be enormous. Therefore, the paper proposes a new adaptive velocity-dependent proportional-integral controller. The relationship between the proportional-integral parameters and the linear velocity is achieved by fitting the experimental results. The adaptive and traditional controllers are compared against each other in some examples. The experiments demonstrate that the adaptive controller decreases the control errors in the z-direction to a half, which provides more precise AFM images. LAY DESCRIPTION: Typically, the scanner follows a triangular waveform in fast axis (x-axis), and follows a very slow ramp signal in the slow axis (y-axis) of conventional AFM. This scanning mode can be called raster scan. However, the triangular waveform contains high-order Fourier harmonics, vibrating the scanner and distorting the image easily. In high-speed AFM, the effect of the high-order Fourier harmonics will be more severe. The above problems can be solved by replacing triangular waves with single-tone sinusoidal waveform. Therefore, the sinusoidal-raster scan and nonraster scan based on the sinusoidal waveform are widely used in high-speed atomic force microscopy. However, the nonlinearly scan path will cause a variable relative linear velocity between the sample and the tip. If a standard proportional-integral controller is still used as a feedback controller in Z direction, the control errors will be large, and this difference will be evident at high-speed scanning. Thus, the paper proposes a new adaptive velocity-dependent proportional-integral controller to solve this problem. Experiments show that the control errors obtained by using the adaptive controller is about a half of that without using it. These illustrate that the proposed method can improve the image quality of the AFM at both low and high scan speeds.

[An study on the incidence of heat stroke and explore it's prediction model in Pudong New Area of Shanghai from 2013-2017]

Objective: To know the incidence of heat stroke and explore it's prediction model in Pudong New Area of Shanghai. Methods: An epidemiological investigation was conducted on heat stroke cases in Pudong New Area of Shanghai from 2013 to 2017. Daily temperature data during this period were collected to explore it's influence. Results: 246 heat stroke cases were reported and investigated, 70.3% (173/246) of them were male. 170 cases are severe heat stroke, accounting for 69.1%. 28 patients died, accounting for 11.4% of all cases of heat stroke, and 16.5% (28/170) of severe heat stroke cases. Thermoplegia (56.5%, 96/170) was the most popular type among severe heat stroke cases. Heat prostration, heat cramps and mixed type account for 17.1% (29/170) , 12.4% (21/170) and 14.0% (24/170) respectively. Scatter plot and linear regression demonstrated that there was a significant linear relation between number of high temperature days and number of heat stroke cases (P<0.01) . And the prediction model is: Predictive number of annual heat stroke cases=β×Number of annual high temperature days+Intercept. Leave-one-out cross validation result shows that the predictive number of annual heat stroke cases from 2013 to 2017 were 85.7%, 90.9%, 83.3%, 91.9 and 84.3% respectively. Conclusion: There was a significant linear relation between number of high temperature days and number of heat stroke cases in Pudong New Area. The related work arrangement for heat stroke prevention could be well planed according to the prediction model.

The p38 mitogen activated protein kinase regulates β-amyloid protein internalization through the α7 nicotinic acetylcholine receptor in mouse brain

Alzheimer's disease (AD) is one of the most devastating neurodegenerative disorders. Intracellular β-amyloid protein (Aβ) is an early event in AD. It induces the formation of amyloid plaques and neuron damage. The α7 nicotinic acetylcholine receptor (α7nAChR) has been suggested to play an important role in Aβ caused cognition. It has high affinity with Aβ and could mediate Aβ internalization in vitro. However, whether in mouse brain the p38 MAPK signaling pathway is involved in the regulation of the α7nAChR mediated Aβ internalization and their role in mitochondria remains little known. Therefore, in this study, we revealed that Aβ is internalized by cholinergic and GABAergic neurons. The internalized Aβ were found deposits in lysosomes/endosomes and mitochondria. Aβ could form Aβ-α7nAChR complex with α7nAChR, activates the p38 mitogen activated protein kinase (MAPK). And the increasing of α7nAChR could in return mediate Aβ internalization in the cortex and hippocampus. In addition, by using the α7nAChR agonist PNU282987, the p38 phosphorylation level decreases, rescues the biochemical changes which are tightly associated with Aβ-induced apoptosis, such as Bcl2/Bax level, cytochrome c (Cyt c) release. Collectively, the p38 MAPK signaling pathway could regulate the α7nAChR-mediated internalization of Aβ. The activation of α7nAChR or the inhibition of p38 MAPK signaling pathway may be a beneficial therapy to AD.

Improvement of wound healing by regulated oxygen-enriched negative pressure-assisted wound therapy in a rabbit model

BACKGROUND

Development of drug therapies and other techniques for wound care have resulted in significant improvement of the cure rate and shortening of the healing time for wounds. A modified technique of regulated oxygen-enriched negative pressure-assisted wound therapy (RO-NPT) has been reported.

AIM

To evaluate the efficacy and impact of RO-NPT on wound recovery and inflammation.

METHODS

Infected wounds were established on 40 adult female white rabbits, which were then randomized to one of four groups: O₂ group, regulated negative pressure-assisted wound therapy (RNPT) group, regulated oxygen-enriched negative pressure-assisted wound therapy (RO-NPT) group and healthy control (HC) group. Each day, the O₂ group was treated with a constant oxygen supply (1 L/min) to the wound, while the RNPT group was treated with continuous regulated negative pressure (70 ± 5 mmHg) and the RNPT + O₂ group was treated with both. The HC group was treated with gauze dressing alone, which was changed every day. Leucocyte count, colony count and wound-healing rate were calculated. Levels of tumour necrosis factor (TNF)-α, interleukin (IL)-1β and IL-8 were evaluated by ELISA.

RESULTS

RO-RNPT significantly decreased bacterial count and TNF-α level, and increased the wound-healing rate. IL-1β, IL-8 and leucocyte count had a tendency to increase in the early phase of inflammation and a tendency to decrease in the later phase of inflammation in the RO-RNPT group.

CONCLUSIONS

RO-NPT therapy assisted wound recovery and inflammation control compared with the RNPT and oxygen-enriched therapies. RO-NPT therapy also increased levels of IL-1β and IL-8 and attenuated expression of TNF-α in the early phase of inflammation.

Methemoglobin-Based Biological Dose Assessment for Human Blood

Methemoglobin is an oxidative form of hemoglobin in erythrocytes. The authors' aim was to develop a new biological dosimeter based on a methemoglobin assay. Methemoglobin in peripheral blood (of females or males) that was exposed to a Co source (0.20 Gy min) was quantified using an enzyme-linked immunosorbent assay. The dose range was 0.5-8.0 Gy. In a time-course experiment, the time points 0, 0.02, 1, 2, 3, 7, 15, 21, and 30 d after 4-Gy irradiation of heparinized peripheral blood were used. Methemoglobin levels in a lysed erythrocyte pellet from the irradiated blood of females and males increased with the increasing dose. Methemoglobin levels in female blood irradiated with γ-doses more than 4 Gy were significantly higher than those in male samples at the same doses. Two dose-response relations were fitted to the straight line: one is with the correlation coefficient of 0.98 for females, and the other is with the correlation coefficient of 0.99 for males. The lower limit of dose assessment based on methemoglobin is about 1 Gy. Methemoglobin levels in blood as a result of auto-oxidation increase after 7-d storage at -20 °C. The upregulation of methemoglobin induced by γ-radiation persists for ∼3 d. The absorbed doses that were estimated using the two dose-response relations were close to the actual doses. The results suggest that methemoglobin can be used as a rapid and accurate biological dosimeter for early assessment of absorbed γ-dose in human blood.

The p38 mitogen-activated protein kinase signaling pathway is involved in regulating low-density lipoprotein receptor-related protein 1-mediated β-amyloid protein internalization in mouse brain

Alzheimer's disease (AD) is one of the most common neurodegenerative diseases. Recently, increasing evidence suggests that intracellular β-amyloid protein (Aβ) alone plays a pivotal role in the progression of AD. Therefore, understanding the signaling pathway and proteins that control Aβ internalization may provide new insight for regulating Aβ levels. In the present study, the regulation of Aβ internalization by p38 mitogen-activated protein kinases (MAPK) through low-density lipoprotein receptor-related protein 1 (LRP1) was analyzed in vivo. The data derived from this investigation revealed that Aβ1-42 were internalized by neurons and astrocytes in mouse brain, and were largely deposited in mitochondria and lysosomes, with some also being found in the endoplasmic reticulum. Aβ1-42-LRP1 complex was formed during Aβ1-42 internalization, and the p38 MAPK signaling pathway was activated by Aβ1-42 via LRP1. Aβ1-42 and LRP1 were co- localized in the cells of parietal cortex and hippocampus. Furthermore, the level of LRP1-mRNA and LRP1 protein involved in Aβ1-42 internalization in mouse brain. The results of this investigation demonstrated that Aβ1-42 induced an LRP1-dependent pathway that related to the activation of p38 MAPK resulting in internalization of Aβ1-42. These results provide evidence supporting a key role for the p38 MAPK signaling pathway which is involved in the regulation of Aβ1-42 internalization in the parietal cortex and hippocampus of mouse through LRP1 in vivo.

Mitogen-activated protein kinase signaling pathways are involved in regulating α7 nicotinic acetylcholine receptor-mediated amyloid-β uptake in SH-SY5Y cells

Intraneuronal accumulation of beta-amyloid protein (Aβ) is an early pathological change in Alzheimer's disease (AD). Recent studies demonstrate that α7 nicotinic acetylcholine receptor (α7nAChR) binds to soluble Aβ with a high affinity. In vitro and in vivo experiments also show that Aβ activates p38 MAPK and ERK1/2 signaling pathways via the α7nAChR. Interestingly, it has been reported that p38 MAPK and ERK1/2 signaling pathways affect the regulation of receptor-mediated endocytosis. These data suggest that MAPK signaling pathways maybe involved in the regulation of α7nAChR-mediated Aβ uptake. However, the evidence for this hypothesis is lacking. In the present study, we examined whether Aβ1-42 oligomers activate MAPK signaling pathways via α7nAChR, and assessed the role of MAPK signaling pathways in the regulation of Aβ1-42 uptake by α7nAChR. We confirm that undifferentiated SH-SY5Y cells are capable of taking up extracellular Aβ1-42. The internalization of Aβ1-42 accumulates in the endosomes/lysosomes and mitochondria. MAPK signaling pathways are activated by Aβ1-42 via α7nAChR. Aβ1-42 and α7nAChR are co-localized in SH-SY5Y cells and the expression of α7nAChR involves in Aβ1-42 uptake and accumulation in SH-SY5Y cells. Our data demonstrate that Aβ1-42 induces an α7nAChR-dependent pathway that relates to the activation of p38 MAPK and ERK1/2, resulting in internalization of Aβ1-42. Our findings suggest that α7nAChR and MAPK signaling pathways play an important role in the uptake and accumulation of Aβ1-42 in SH-SY5Y cells. Blockade of α7nAChR may have a beneficial effect by limiting intracellular accumulation of amyloid in AD brain and serves a potential therapeutic target for AD.

Development of serum zinc as a biological dosimeter in mice

PURPOSE

To develop a new biological dosimeter based on serum zinc concentration.

MATERIALS AND METHODS

Male mice (8 weeks old) were exposed to different doses (0, 1.0, 2.0, 4.0, or 8.0 Gy) of gamma rays from a (60)Co source. Blood was then collected from the orbital area of these mice, and the serum zinc concentration was detected using the 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol colorimetric method. The data were analyzed using one-way analysis of variance.

RESULTS

The serum zinc concentration in the irradiated mice decreased with increasing dose. Two dose-response relationships fitted to the linear quadratic curve were obtained: One immediately after exposure (y = 0.010x(2) - 0.133x + 0.663, r = 0.983) and the other on the seventh day after exposure (y = 0.008x(2) - 0.127x + 0.695, r = 0.990). The serum zinc concentration continued to decrease until 21 days after exposure. The absorbed doses estimated using both dose-response relationships were close to the actual doses.

CONCLUSIONS

Serum zinc is a quick, effective, and sensitive biomarker for early biological doses assessment of mice irradiated by gamma radiation.

Vasoactive intestinal peptide protects against ischemic brain damage induced by focal cerebral ischemia in rats

Vasoactive intestinal peptide (VIP) exerts neuroprotective effects under various neurotoxic conditions in vitro. In the present study, we investigated the effects of VIP on transient ischemic brain damage. Focal cerebral ischemia was induced using middle cerebral artery occlusion (MCAO) for 120 min in the adult rat brain. Either a single intracerebroventricular injection of VIP or saline was given at the beginning of reperfusion. Forty-eight hours after MCAO, the rats were sacrificed for evaluation of the infarct volume and histological analysis. ELISA was performed to assay levels of serum S100B before being sacrificed. We also evaluated the blood-brain barrier (BBB) permeability using Evans blue dye injection method. In contrast to the cases treated with vehicle, the infarct volume was significantly (P<0.05) reduced, and terminal deoxynucleotidyl transferase-mediated dUTP-nick end labeling (TUNEL) staining and immunoreactivity for S100B were also significantly (P<0.05) decreased in the ischemic hemisphere with VIP treatment. In addition, the elevations of serum S100B were significantly (P<0.01) attenuated in VIP-treated rats compared with those of control rats. Treatment with VIP did not result in a significant reduction of Evans blue leakage, although it tended to be lower than that in the control rats. Our data suggest that treatment with VIP reduces brain damage in ischemic rats, and this effect may be associated with the attenuation of apoptosis and S100B expression.

Effect of subcutaneous injection of [Ala]16-aFGF(1-29) on slow transit constipation in mice

AIM: To investigate the potential therapeutical effect of a new acidic fibroblast growth factor (aFGF) fragment - [Ala]¹⁶-aFGF(1-29) against slow transit constipation (STC) in mice and to explore possible mechanisms involved.

METHODS: Sixty ICR mice were divided randomly and equally into test group and control group. A mouse model of STC was established by subcutaneous injection (SC) of morphine [2.5 mg/(kg•d)] for 45 days. The control group was treated with normal saline for the same duration. The fecal character was observed according to the Bristol Stool Form Scale (BSFS), and only mice producing stools conforming to BSFS 1 and 2 were used as STC models. On day 45, six mice were chosen randomly from each group and used to confirm if STC was successfully induced by charcoal propulsion test. The rest mice in each group were divided into test group 1, test group 2, control group 1, and control group 2 (n = 12 each). The test group 1 and control group 1 were treated with [Ala]¹⁶-aFGF(1-29) (300 µg/kg each time, SC) twice per week for 8 weeks, while the test group 2 and control group 2 were treated with the same volume of vehicle. Fecal character was observed in all mice. Eight weeks later, the intestinal propulsion rate (IPR) in mice of each group was measured and the expression of neuron-specific enolase (NSE, a neuronal maker) in the colon was detected by immunohistochemistry and Western blot.

RESULTS: On day 45, the feces in the test group was drier and harder (BSFS 1 and 2) than the control group (BSFS 4 and 5). Both the IPR and expression level of NSE in the test group were significantly lower than those in the control group (63.422% ± 1.791% vs 55.702% ± 1.806%, 1.18800 ± 0.03176 vs 0.88730 ± 0.03554, 0.90520 ± 0.02268 vs 0.71300 ± 0.01654, all P < 0.05 or 0.01). Eight weeks after treatment, the feces in the test group 1 gradually became as smooth and soft (BSFS 4 and 5) as that in the control groups 1 and 2; the IPR and expression level of NSE in colonic tissue in the test group 1 were obviously improved compared to the test group 2 (62.250% ± 5.283% vs 57.190% ± 4.291%, 0.6543 ± 0.0069 vs 0.4193 ± 0.0158, 0.5823 ± 0.019 vs 0.5171 ± 0.0124, all P < 0.05) but showed no significant difference with those in the control groups 1 and 2.

CONCLUSION: Treatment with [Ala]¹⁶-aFGF (1-29) improved constipation symptoms and IPR in STC mice at least partially by protection of the enteric nervous system.

Separation of anthocyanins from Perilla frutescens by high speed countercurrent chromatography

OBJECTIVE

To develop an efficient method for the separation of anthocyanins from Perilla frutescens.

METHODS

Freeze-dried Perilla frutescens was extracted with 1% HCl. After purified by Amberlite XAD-7 column chromatography, the bioactive anthocyanins were separated by high-speed countercurrent chromatography (HSCCC). The structures of the compounds were elucidated by 1H- and 13C-NMR spectroscopy.

RESULTS

When the HSCCC separation was performed with a two-phase solvent system composed of n-butanol-tert-butyl methyl ether-acentonitrile-water (2:2:1:5 + 0.1% TFA) by eluting the mobile phase at a flow rate of 3.0 mL/min and a revolution speed of 800 r/min, 10.1 mg malonylshisonin and 8.6 mg shisonin were obtained from 1.0 g of the XAD-7 extract. The purities of malonylshisonin and shisonin were 96.7% and 97.5%, respectively.

CONCLUSION

HSCCC is a fast and efficient technique to prepare pure malonylshisonin and shisonin from Perilla frutescens.

Protective effect of ginsenoside Rb1 on beta-amyloid protein(1-42)-induced neurotoxicity in cortical neurons

The effects of ginsenosides were thought to prevent neurodegenerative processes associated with aging. The accumulation of beta-amyloid protein (Abeta) within the brain is one of the pathological hallmarks of Alzheimer's disease (AD). There is no one effective treatment of AD. To investigate the effects of ginsenoside Rb1 (GRb1) on neuronal damage induced by Abeta and potential mechanisms of the effects of GRb1 in vitro, morphological observation and biochemical analysis combining primary cultured neurons were adopted. A positive control was pre-treated with Trolox. Neurons that were treated with Abeta 1-42 (2 muM) were shrunken perikaryon with loss of neurite processes; the survival rate of neurons decreased almost to 50% (p<0.01). Lactate dehydrogenase (LDH) release, malondialdehyde (MDA) product and superoxide dismutase (SOD) activity level all increased obviously (p<0.01 or p<0.05). However, neurons pre-treated with GRb1 (0.1, 1 and 10 muM) or Trolox (10 muM) had a survival rate increase compared with neurons treated with Abeta alone; LDH release and MDA product decreased distinctly, and the increase in SOD activity in Abeta-treated neurons was attenuated evidently (p<0.01 or p<0.05). Thus, we conclude that GRb1 exerted neuroprotection obviously. GRb1 protected neurons against the toxicity of Abeta, most likely through an antioxidant pathway. GRb1 could be useful neuroprotective agents of AD.

A combined DNA vaccine-prime, BCG-boost strategy results in better protection against Mycobacterium bovis challenge

In this study, we demonstrated that calves vaccinated with a combined DNA vaccine encoding Ag85B, MPT- 64, and MPT-83 antigens from the Mycobacterium tuberculosis for the priming and subsequently boosting with BCG prior to experimental challenge with virulent Mycobacterium bovis (M. bovis) resulted in improved immune responses over immunizing. Vaccination with the combined DNA/BCG induced higher levels of antigen- specific gamma interferon (IFN-gamma) in whole-blood cultures 4 weeks after final vaccination and the level of antigen-specific IFN-gamma in response to Ag85, MPT-64, and MPT-83 were still higher 4 weeks after challenge when compared to the combined DNA group. There was a significant bias toward induction of CD4+ T cells rather than CD8+ T cells responses, and the mean percentage of CD4+ T cells was increased about 2.6-fold in peripheral blood mononuclear cells (PBMC) cultures in DNA prime-BCG boost vaccination when compared to the nonvaccinated group. In addition, DNA prime-BCG boost vaccination resulted in stronger humoral immune responses, and the levels of the specific antibodies to three antigens were increased two- to 32- fold when compared to the combined DNA group. Vaccination with the combined DNA/BCG induced a high level of protection against an intratracheal challenge with virulent M. bovis, based on a significant enhancement of six pathological and microbiological parameters of protection compared to the nonvaccinated group. Finally, the combined DNA/BCG increased the protective efficacy by more than 10-100-fold as measured by reduced CFU counts in the lungs from calves challenged with M. bovis compared to the combined DNA and BCG groups. These results suggest that use of the prime-boost strategy offers better protection against bovine tuberculosis than does the combined DNA vaccines and BCG.

Combined DNA vaccine encapsulated in microspheres enhanced protection efficacy against Mycobacterium tuberculosis infection of mice

In a study to develop novel vaccination strategies against tuberculosis, we encapsulated DNA encoding Ag85B, MPT-64 and MPT-83 antigens mixed with dimethyldioctyldecyl ammonium bromide (DDA) into biodegradable poly(dl-lactide-co-glycolide, PLGA) microspheres. Scanning electron microscopy (SEM) analysis demonstrated a uniform microsphere population with a mean diameter of <5microm. Using RT-PCR we were able to demonstrate antigen gene expression in selected tissue. Moreover, in mice injected with PLGA encapsulated DNA, the levels of expression appeared to be higher comparing to those injected with non-encapsulated DNA. Also, C57BL/6 mice immunized with a single dose of PLGA encapsulated DNA produced increased levels of IFN-gamma in the supernatant of spleen cells when cultured in the presence of the recombinant antigens. High levels of specific IgG antibody against the three antigens were also observed. In vaccine/challenge experiments, mice receiving a single dose of PLGA encapsulated DNA were protected against Mycobacterium tuberculosis challenge at levels comparable to groups of mice immunized with three doses of non-encapsulated DNA vaccine or with Mycobacterium bovis BCG.

Combined DNA vaccines formulated either in DDA or in saline protect cattle from Mycobacterium bovis infection

We tested the effectiveness of combined DNA vaccines encoding antigens Ag85B, MPT64 and MPT83 from Mycobacterium tuberculosis on cattle. Our results showed that calves treated with combined DNA vaccines in the presence of dimethyldioctyldecyl ammonium bromide (DDA) or saline elicited a strong gamma interferon (IFN-gamma) response 1 or 2 months after the third vaccination. All three antigens induced substantial levels of IFN-gamma production 1 month after the bacterial challenge, when the BCG-driven IFN-gamma levels dropped to less than one third of their peak values. Animals receiving combined DNA vaccines produced highest amounts of IgG antibody titer 2 months after the third vaccination. Steady state low IgG levels were found 2 months after bacterial challenge. A few small lung and lymph node lesions were detected in 1/5 animals treated with combined DNA vaccines, whereas 3/5 of BCG-treated and 5/5 of vector-control calves showed larger and significantly more lesions. About 70- to 100-fold fewer bacteria were found in the lungs and lymph nodes of combined DNA vaccine-treated animals compared to those of the control group. Histopathological analyses showed that vaccinated calves possessed substantially improved post-infection lung and lymph node pathology relative to the controls. Our data indicate that combined DNA vaccines may be used in cattle to combat bovine tuberculosis.

Combined DNA Vaccines Formulated in DDA Enhance Protective Immunity against Tuberculosis

This study evaluated the adjuvant Dimethyldioctyldecyl Ammonium Bromide (DDA) effect on the protective immunity induced by a combination of plasmids containing genes encoding antigens Ag85B, MPT-83, and ESAT-6 from Mycobacterium tuberculosis. The combined DNA vaccines in DDA resulted in significant increases in both specific IgG and splenic T-cell-derived Th1-type cytokine gamma interferon (IFN-gamma) production in response to the three purified antigens when compared to that of combined DNA vaccines in saline. Vaccines in DDA increased the protective efficacy of mice challenged with M. tuberculosis H37Rv as measured by reduced relative CFU counts in their lungs. Mice immunized with the combined DNA vaccines were shown to limit the growth of tubercle bacilli both in lungs and in spleens. Histopathological analyses showed that vaccinated mice had substantially improved postinfection lung pathology relative to the controls. We suggest that our combination of antigens together with DDA formulation may provide a new insight into tuberculosis prevention.

DDPH inhibited L-type calcium current and sodium current in single ventricular myocyte of guinea pig

AIM

To investigate the effects of 1-(2, 6-dimethylphenoxy)-2-(3,4-dimethoxyphenyl-ethylamino)propane hydrochloride (DDPH) on L-type calcium current (ICa) and sodium current (INa), and to compare its inhibitory potency with verapamil and mexiletine.

METHODS

Whole-cell patch clamp technique was used to record ICa and INa in a single ventricular myocytes of guinea pig.

RESULTS

(1) DDPH (3 - 300 micromol . L-1) decreased ICa at 0 mV in a concentration-dependent manner with an IC50 value of 28.5 micromol . L-1 (95 % confidence limits: 14.3 - 42.7 micromol . L-1, n = 8 cells from 8 guinea pigs). Verapamil (0.3 - 30 micromol . L-1) reduced ICa with an IC50 value of 1.8 micromol . L-1 (95 % confidence limits: 1.3 - 2.3 micromol . L-1, n = 6 cells from 6 guinea pigs). Mexiletine 100 micromol . L-1 did not affect ICa (n = 5 cells from 5 guinea pigs, P > 0.05). The degree of use-dependent blocking effect of DDPH 30 micromol/L on ICa was 58 % +/- 13 % (n = 5 cells from 5 guinea pigs, P < 0.01) at 1 Hz and 76 % +/- 11 % (n = 5 cells from 5 guinea pigs, P < 0.01) at 3 Hz. (2) DDPH (20 - 320 micromol . L-1) could also block INa in a concentration-dependent manner with an IC50 value of 89.0 micromol . L-1 (95 % confidence limits: 68.7 - 109.3 micromol . L-1, n = 9 cells from 9 guinea pigs). The IC50 value of mexiletine was 32.2 micromol . L-1 (95 % confidence limits: 11.7 - 52.7 micromol . L-1, n = 5 cells from 5 guinea pigs). Verapamil at the concentration of 10 micromol . L-1 did not affect INa (n = 5 cells from 5 guinea pigs, P > 0.05). The blocking effect of DDPH 80 micromol/L on INa was non use-dependent.

CONCLUSION

DPH exhibited inhibitory effects on both ICa and INa, but its inhibitory effect on ICa was weaker than verapamil, and on INa was weaker than mexiletine.

[Clinical features and prognosis of paroxysmal atrial fibrillation in the elderly]

Eighty one elderly patients with paroxysmal atrial fibrillation were studied with respect to clinical features, effect of antiarrhythmic drugs and prognosis. 35 (43.2%) patients were associated with coronary artery disease and/or hypertension, while 23 (28.4%) patients had no other cardiovascular diseases. The latter condition was significantly less in patients over 60 years old when they had the first paroxysmal attack. Atrial fibrillation became permanent in 18 (22.2%) patients. Left atrial enlargement and abnormal cardiac function were significant independent factors affecting the type of atrial fibrillation. During an observation period of 12-84 months, the incidence of cerebral embolism and cardiac death were 6.1% and 4.9% respectively in all cases. We did not find that the prognosis of patients was affected by the types of atrial fibrillation.

[A clinical study of aortic dissecting]

The clinical features, etiologies, pathogenesis, treatment and prognosis of 70 patients with aortic dissecting were studied. Patients with age ranging from 31 to 70 years consisted 93% of the total. The proportion of proximal to distal types is 0.8: 1. Hypertension was present in 67% and Marfan's syndrome 18% of the patients. The pathologic finding was scattered rupture with myxomatous and cystic necrosis of the mecial elastic fibers. 80% of the patients suffered from the disease without any inducing cause. Of the 76% patients had chest pain, it was very severe in 69%. Chest X-ray, ultrasound, computed tomography and magnetic resonance imaging together with clinical manifestations may accurately diagnose the disease. The sensitivity and specificity of the ultrasound are 97% and 94% respectively. The mortality in hospital with surgical and medical therapy of the proximal type was 14% and 22% respectively, while that of the distal type was 63% and 27% respectively. Rupture of the aneurysm was the cause of death in 68% of the patients.

[Preliminary results of three different cannulations for percutaneous transhepatic cholecystic drainage in the interventional gallstone dissolutions]

Three different methods of percutaneous transhepatic gallbladder cathetering drainage were applied in 33 patients undergoing interventional gallstone dissolution. Among them, sheathed needle was used in 6 cases with a success rate of 33%; wire-guided in 16 with a success rate of 50%; and double-sheathed inner needle was successfully used in all the 11 cases. The authors believe that this last method could safely be used in the nonoperative drainage of acute cholecystitis as well as the interventional gallstone dissolutions.

[Diabetic myocardiopathy]

Three cases of diabetic myocardiopathy having history of diabetes, angina and left ventricular dysfunction of various degrees and confirmed by coronary angiography and endomyocardial biopsy were reported. Electrocardiography showed significant ST-T changes simulating coronary insufficiency but without definite localization. As to the treatment, nitrate preparations, inotropic agents such as strophanthin K, digoxin etc. were used to relieve the symptoms; insulin was also administered to control the blood glucose level. Diltiazem, a calcium blocker, is also of help in alleviating the symptoms. It is shown in the present study and in the literatures as well that diabetic myocardiopathy is a disease showing intramural microvascular endothelial proliferation and swelling as well as subendothelial accumulation of acid glycogen deposition cells. The transportation of intracellular calcium ions and the cellular metabolism are thus affected, so there are extensive ischemia, focal necrosis and fibrosis in the myocardium with resulting cardiac dysfunction. The authors are, therefore, of the opinion that diabetic myocardiopathy is a specific and separate clinical entity.

[Correlation among electrocardiogram, important risk factors of coronary artery diseases and coronary lesion in patients with chest pain]

Clinical and angiographic data from 103 patients with chest pain were evaluated to determine their correlation with ST-T abnormality in resting electrocardiogram. Univariate analysis suggested that male sex, hypertension, old myocardial infarction, severe coronary lesion, multiple vessel lesion and left ventricular wall motion abnormality significantly increase the likelihood of ST-T abnormality. Multivariate analysis suggested that male sex, hypertension and left ventricular wall motion abnormality were significant independent predictors of abnormal ST-T. It is essential to improve the electrocardiographic accuracy of diagnosing CAD so as to help clinical doctors in preventing and treating this disease.