Gastrointestinal syndrome encountered during a train voyage to high altitudes: A 14-day survey of 69 passengers in China.

BACKGROUND: The diagnosis and evaluation of the severity of acute mountain sickness (AMS) continue to be problematic due to a lack of consensus on the inclusion of symptoms in a scoring system. Recent investigations highlight the significance of gastrointestinal symptoms in identifying this condition. However, the specific gastrointestinal symptoms associated with AMS have not been thoroughly elucidated in previous studies, and the underlying risk factors remain inadequately comprehended. METHODS: This study aimed to investigate the characteristics, trends, and risk factors related to gastrointestinal symptoms encountered during train travel to high altitude. A total of 69 passengers, specifically all with medical backgrounds, were surveyed 6 times over a period of 14 days. RESULTS: The daily incidence of abdominal discomfort was higher than non-gastrointestinal symptoms within 14 days. Gastrointestinal symptoms demonstrated a greater prevalence, longer duration, and increased risk compared to non-gastrointestinal symptoms, such as headaches. The symptoms of abdominal distension and bowel sound hyperaction were found to be prevalent and persistent among patients diagnosed with AMS, exhibiting a high incidence rate. Gender, age, body mass index (BMI), smoking habits, and alcohol consumption were identified as risk factors associated with the occurrence and duration of gastrointestinal symptoms. CONCLUSION: This study suggests that gastrointestinal symptoms are more common and persistent when traveling to the plateau by train. These symptoms should be taken into consideration in the further diagnosis and prevention of AMS. Therefore, this study provides a significant theoretical foundation for the prevention and treatment of AMS.

Synthesis of pyrazino[1,2-b]indazoles via cascade cyclization of indazole aldehydes with propargylic amines.

An efficient intermolecular annulation of indazole aldehydes with propargylic amines has been developed for the synthesis of pyrazinoindazoles under catalyst- and additive-free conditions. This straightforward methodology was found to feature a wide substrate scope, high atom economy and environmental advantages. The bioactivity results of these new pyrazino[1,2-b]indazoles showed that some of them exhibited significant antifungal activity.

Activation of mucosal insulin receptor exacerbates intestinal inflammation by promoting tissue resident memory T cells differentiation through EZH2.

BACKGROUND: Inflammatory Bowel Diseases (IBD), an autoimmune disease characterised by abnormal intestinal immunity, are related to vital morbidity around the world. However, therapeutic agents for IBD have not achieved desired benefit. Exploring new therapeutic targets for IBD, especially based on its abnormally intestinal immunity, could alleviate the flare-up and worsening of IBD. Tissue resident memory T cells (TRM) are core of multiple autoimmune diseases, including IBD. However, the mechanism of TRM differentiation remains to be investigated. METHODS: The alterations in mRNA and lncRNA profile of intestinal intraepithelial lymphocytes (IELs), the largest component of intestinal TRM, were analyzed in DSS-induced chronic colitis. Based on it, we examined the function of rectal insulin instillation in a dextran sodium sulfate (DSS) induced chronic colitis. Furthermore, we investigated the downstream-target of the insulin pathway-EZH2 and the crucial role of EZH2 in intestinal tissue resident memory T cell differentiation by utilizing EZH2fl/flCD4cre mice. RESULTS: Insulin receptor (INSR) expression was found to be significantly reduced. Activation of mucosal insulin pathway by rectal insulin instillation exacerbated colitis by disrupting IELs subgroups and up-regulating TNF-ɑ and IL-17 expression. Rectal insulin instillation promoted EZH2 expression and EZH2 inhibition alleviated chronic colitis. EZH2fl/flCD4cre mice restored the normal IEL subgroups and suppressed TNF-ɑ and IL-17 expression, exhibiting alleviated colitis. IELs from EZH2fl/flCD4cre mice exhibit significant changes in TRM related phenotype. CD4+TRM was significantly increased in chronic colitis and decreased in EZH2fl/flCD4cre mice. CONCLUSION: Insulin receptor of intestinal mucosal T-cells could promote intestinal TRM differentiation via EZH2. Our discoveries suggest that therapies targeting colonic INSR and EZH2 could be potential treatment for IBD based on its regulatory effects on TRM. Insulin receptor inhibitors rather than insulin should be applied during colitis-active phase. In addition, EZH2 shows to be a downstream signal of the insulin pathway and EZH2 inhibitor could alleviating intestinal inflammation. However, the critical role of EZH2 in TRM differentiation restricts the anti-tumor effects of EZH2 inhibitor in vivo.

Enteric glial cells aggravate the intestinal epithelial barrier damage by secreting S100ß under high-altitude conditions.

Damage to the intestinal epithelial barrier (IEB) has been reported under high-altitude (HA) conditions and may be responsible for HA-associated gastrointestinal (GI) disorders. However, this pathogenetic mechanism does not fully explain the GI stress symptoms, such as flatulence and motility diarrhea, which accompany the IEB damage under HA conditions, especially for the people exposed to HA acutely. In the present study, we collected the blood samples from the people who lived at HA and found the concentration of enteric glial cells (EGCs)-associated biomarkers increased significantly. HA mouse model was then established and the results revealed that EGCs were involved in IEB damage. Zona occludens (ZO)-1, occludin, and claudin-1 expression was negatively correlated with that of glial fibrillary acidic protein (GFAP) and S100ß under HA conditions. In order to learn more about how EGCs influence IEB, the in vitro EGC and MODE-K hypoxia experiments that used hypoxic stimulation for simulating in vivo exposure to HA was performed. We found that hypoxia increased S100ß secretion in EGCs. And MODE-K cells cultured in medium conditioned by hypoxic EGCs showed low ZO-1, occludin, and claudin-1 levels of expression. Furthermore, treatment of MODE-K cells with recombinant mouse S100ß resulted in diminished levels of ZO-1, occludin, and claudin-1 expression. Thus, HA exposure induces greater S100ß secretion by EGCs, which aggravates the damage to the IEB. This study has revealed a novel mechanism of IEB damage under HA conditions, and suggest that EGCs may constitute a fresh avenue for the avoidance of GI disorders at HA.

Enteric fungi protect against intestinal ischemia-reperfusion injury via inhibiting the SAA1-GSDMD pathway.

INTRODUCTION: Prophylactic antifungal therapy has been widely used for critical patients, but it has failed to improve patient prognosis and has become a hot topic. This may be related to disruption of fungal homeostasis, but the mechanism of fungi action is not clear. As a common pathway in critical patients, intestinal ischemia-reperfusion (IIR) injury is fatal and regulated by gut microbiota. However, the exact role of enteric fungi in IIR injury remains unclear. OBJECTIVES: This is a clinical study that aims to provide new perspectives in clarifying the underlying mechanism of IIR injury and propose potential strategies that could be relevant for the prevention and treatment of IIR injury in the near future. METHODS: ITS sequencing was performed to detect the changes in fungi before and after IIR injury. The composition of enteric fungi was altered by pretreatment with single-fungal strains, fluconazole and mannan, respectively. Intestinal morphology and function impairment were evaluated in the IIR injury mouse model. Intestinal epithelial MODE-K cells and macrophage RAW264.7 cells were cultured for in vitro tests. RESULTS: Fecal fungi diversity revealed the obvious alteration in IIR patients and mice, accompanied by intestinal epithelial barrier dysfunction. Fungal colonization and mannan supplementation could reverse intestinal morphology and function impairment that were exacerbated by fluconazole via inhibiting the expression of SAA1 from macrophages and decreasing pyroptosis of intestinal epithelial cells. Clodronate liposomes were used to deplete the number of macrophages, and it was demonstrated that the protective effect of mannan was dependent on macrophage involvement. CONCLUSION: This finding firstly validates that enteric fungi play a crucial role in IIR injury. Preventive antifungal treatment should consider damaging fungal balance. This study provides a novel clue to clarify the role of enteric fungi in maintaining intestinal homeostasis.

Dissecting the effect of ileal faecal diversion on the intestine using single-cell sequencing.

BACKGROUND: Although ileal faecal diversion is commonly used in clinical settings, complications accompany it. Elucidating the intestinal changes caused by ileal faecal diversion will help resolve postoperative complications and elucidate the pathogenic mechanisms of associated intestinal disorders, such as Crohn's disease (CD). Therefore, our study aimed to provide new insights into the effects of ileal faecal diversion on the intestine and the potential mechanisms. METHODS: Single-cell RNA sequencing was performed on proximal functional and paired distal defunctioned intestinal mucosae from three patients with ileal faecal diversion. We also performed in vitro cellular and animal experiments, tissue staining and analysed public datasets to validate our findings. RESULTS: We found that the epithelium in the defunctioned intestine tended to be immature, with defective mechanical and mucous barriers. However, the innate immune barrier in the defunctioned intestine was enhanced. Focusing on the changes in goblet cells, we demonstrated that mechanical stimulation promotes the differentiation and maturation of goblet cells through the TRPA1-ERK pathway, indicating that the absence of mechanical stimulation may be the main cause of defects in the goblet cells of the defunctioned intestine. Furthermore, we found obvious fibrosis with a pro-fibrotic microenvironment in the defunctioned intestine and identified that monocytes may be important targets for faecal diversion to alleviate CD. CONCLUSIONS: This study revealed the different transcription landscapes of various cell subsets and the potential underlying mechanisms within the defunctioned intestine, when compared to the functional intestine, based on the background of ileal faecal diversion. These findings provide novel insights for understanding the physiological and pathological roles of the faecal stream in the intestine.

The effects of grain size and temperature on mechanical properties of CoCrNi medium-entropy alloy.

CONTEXT: The mechanical properties and deformation mechanisms of CoCrNi medium-entropy alloy are studied through molecular dynamics simulations. The effects of temperature and average grain size on the elastic modulus, Poisson's ratio, yield stress, and maximum flow stress are investigated. METHODS: The constant pressure molecular dynamics method is used to calculate the elastic modulus and Poisson's ratio of the alloy at different temperatures and average grain sizes. Simple tension simulations are conducted to determine the yield stress and maximum flow stress as a function of average grain size. The study also analyzes the dislocation behavior near grain boundaries at different temperatures using molecular dynamics simulations. The Hall-Petch and inverse Hall-Petch relationships are employed to describe the grain size-dependent deformation behavior of the alloy.

Log odds of positive lymph nodes as a novel prognostic predictor for colorectal cancer: a systematic review and meta-analysis.

BACKGROUND: Colorectal cancer (CRC) is the third most prevalent cancer in the world, which remains one of the leading causes of cancer-related deaths. Accurate prognosis prediction of CRC is pivotal to reduce the mortality and disease burden. Lymph node (LN) metastasis is one of the most commonly used criteria to predict prognosis in CRC patients. However, inaccurate surgical dissection and pathological evaluation may lead to inaccurate nodal staging, affecting the effectiveness of pathological N (pN) classification in survival prediction among patients with CRC. In this meta-analysis, we aimed to estimate the prognostic value of the log odds of positive lymph nodes (LODDS) in patients with CRC. METHODS: PubMed, Medline, Embase, Web of Science and the Cochrane Library were systematically searched for relevant studies from inception to July 3, 2021. Statistical analyses were performed on Stata statistical software Version 16.0 software. To statistically assess the prognostic effects of LODDS, we extracted the hazard ratio (HR) and 95% confidence interval (CI) of overall survival (OS) and disease-free survival (DFS) from the included studies. RESULTS: Ten eligible articles published in English involving 3523 cases were analyzed in this study. The results showed that LODDS1 and LODDS2 in CRC patients was correlated with poor OS compared with LODDS0 (LODDS1 vs. LODDS0: HR = 1.77, 95% CI (1.38, 2.28); LODDS2 vs. LODDS0: HR = 3.49, 95% CI (2.88, 4.23)). Meanwhile, LODDS1 and LODDS2 in CRC patients was correlated with poor DFS compared with LODDS0 (LODDS1 vs. LODDS0: HR = 1.82, 95% CI (1.23, 2.68); LODDS2 vs. LODDS0: HR =3.30, 95% CI (1.74, 6.27)). CONCLUSIONS: The results demonstrated that the LODDS stage was associated with prognosis of CRC patients and could accurately predict the prognosis of patients with CRC.

Antifungal Treatment Aggravates Sepsis through the Elimination of Intestinal Fungi.

Prophylactic antifungal therapy is widely adopted clinically for critical patients and effective in reducing the morbidity of invasive fungal infection and improves outcomes of those diagnosed patients; however, it is not associated with higher overall survival. As intestinal commensal fungi play a fundamental role in the host immune response in health and disease, we propose that antifungal therapy may eliminate intestinal fungi and aggravate another critical syndrome, sepsis. Here, with murine sepsis model, we found that antifungal therapy with fluconazole dismissed intestinal fungal burden and aggravated endotoxin-induced but no gram-positive bacteria-induced sepsis. Nevertheless, antifungal therapy did not exert its detrimental effect on germ-free mice. Moreover, colonizing more commensal fungi in the mouse intestine or administration of fungal cell wall component mannan protected the mice from endotoxin-induced sepsis. On the molecular level, we demonstrated that antifungal therapy aggravated endotoxin sepsis through promoting Gasdermin D cleavage in the distal small intestine. Intestinal colonization with commensal fungi inhibited Gasdermin D cleavage in response to lipopolysaccharide challenge. These findings show that intestinal fungi inhibit Gasdermin D-mediated pyroptosis and protect the mice from endotoxin-induced sepsis. This study demonstrates the protective role of intestinal fungi in the pathogenesis of endotoxin-induced sepsis in the laboratory. It will undoubtedly prompt us to study the relationship between antifungal therapy and sepsis in critical patients who are susceptible to endotoxin-induced sepsis in the future.

Galantamine Inhibits Aß1-42-Induced Neurotoxicity by Enhancing α7nAChR Expression as a Cargo Carrier for LC3 Binding and Aß1-42 Engulfment During Autophagic Degradation.

Despite Alzheimer's disease (AD) being the most common neurodegenerative disorder worldwide, no FDA-approved disease-modifying treatments have been approved for this condition since 2003. Neuronal-type alpha7 nicotinic acetylcholine receptors (α7nAChRs) play an essential role in cognitive functions, binding with extracellular ß-amyloid (Aß plaques) and inhibiting Aß-induced neurotoxicity. α7nAChRs are impaired early in the course of AD; drugs targeting α7nAChRs are being hotly pursued as a treatment of AD. Encenicline, a partial selective agonist of α7nAChR and modulator of acetylcholine, failed in phase III trials because of gastrointestinal side effects. We, therefore, evaluated the efficacy of galantamine, a positive allosteric modulator at α7nAChRs and an acetylcholinesterase inhibitor, that has been used since 2000 as first-line treatment of mild-to-moderate dementia. This study highlights an important new benefit with galantamine. We found that galantamine inhibits Aß1-42-induced apoptosis by activating the JNK signaling pathway, thus enhancing α7nAChR expression, and also inhibits the Akt pathway, which further increases autophagosome biogenesis and autophagy. These effects can be reproduced by α7nAChR overexpression in the absence of galantamine. Importantly, the α7 subunit protein sequence of α7nAChRs contains 3 LC3-interacting regions; our immunoprecipitation data show that α7 binds with the autophagosomal marker protein LC3. This is the first report to provide evidence showing that the cell surface receptor α7nAChR acts as a cargo carrier for LC3 binding for Aß1-42 sequestration to autophagosomes, suggesting a novel mechanism for the neuroprotective efficacy of galantamine in AD.

The Effects of Cognitive Reappraisal and Expressive Suppression on Memory of Emotional Pictures.

In the field of emotion research, the influence of emotion regulation strategies on memory with emotional materials has been widely discussed in recent years. However, existing studies have focused exclusively on regulating negative emotion but not positive emotion. Therefore, in the present study, we investigated the influence of emotion regulation strategies for positive emotion on memory. One hundred and twenty college students were selected as participants. Emotional pictures (positive, negative and neutral) were selected from Chinese Affective Picture System (CAPS) as experimental materials. We employed a mixed, 4 (emotion regulation strategies: cognitive up-regulation, cognitive down-regulation, expressive suppression, passive viewing) × 3 (emotional pictures: positive, neutral, negative) experimental design. We investigated the influences of different emotion regulation strategies on memory performance, using free recall and recognition tasks with pictures varying in emotional content. The results showed that recognition and free recall memory performance of the cognitive reappraisal groups (up-regulation and down-regulation) were both better than that of the passive viewing group for all emotional pictures. No significant differences were reported in the two kinds of memory scores between the expressive suppression and passive viewing groups. The results also showed that the memory performance with the emotional pictures differed according to the form of memory test. For the recognition test, participants performed better with positive images than with neutral images. Free recall scores with negative images were higher than those with neutral images. These results suggest that both cognitive reappraisal regulation strategies (up-regulation and down-regulation) promoted explicit memories of the emotional content of stimuli, and the form of memory test influenced performance with emotional pictures.

Strut-based accelerated partial breast irradiation: Report of treatment results for 250 consecutive patients at 5 years from a multicenter retrospective study.

PURPOSE: This registry trial studied the long-term outcomes of women receiving accelerated partial breast irradiation (APBI) using strut-based applicators and reports on the local control, toxicity, and survival for the first 250 patients treated with this device. METHODS AND MATERIALS: Patients were treated using the strut-based brachytherapy device with conventional dose and fractionation of 34 Gy in 10 twice-daily fractions. Planning goals for the planning target volume were V90 > 90%, V150 < 50 cc, and V200 < 20 cc. Toxicity was graded based on the Common Terminology Criteria for Adverse Events v3.0. Recurrence rates were also calculated. RESULTS: Median followup was 59.5 months for the 250 patients. Grade 2 or higher adverse events at any time for hyperpigmentation, induration, erythema, telangiectasia, breast pain, seroma, and fat necrosis were 0.4%, 3.0%, 3.0%, 3.0%, 3.9%, 4.8%, and 1.3%, respectively. The median V90 was 97%, V95 was 95.1%, V150 was 28.7 cc, and V200 was 14.2 cc. For those patients with a less than a 5-mm or 3-mm-skin bridge, the median skin max doses were 272 and 289 cGy, respectively. The 4-year actuarial recurrence rates for true recurrence/marginal miss and ipsilateral breast tumor recurrence were 2.3% and 3.6%, respectively. The 4-year actuarial rates for overall survival, cause-specific survival, and disease-free survival were 97%, 98%, and 92%, respectively. CONCLUSIONS: The strut-based applicator was designed to simplify APBI compared to interstitial brachytherapy. This report confirms excellent tumor control and survival with low toxicity and supports the evidence that brachytherapy has less normal tissue toxicity than APBI with external beam irradiation.

Early exposure of rotating magnetic fields promotes central nervous regeneration in planarian Girardia sinensis.

Magnetic field exposure is an accepted safe and effective modality for nerve injury. However, it is clinically used only as a supplement or salvage therapy at the later stage of treatment. Here, we used a planarian Girardia sinensis decapitated model to investigate beneficial effects of early rotary non-uniform magnetic fields (RMFs) exposure on central nervous regeneration. Our results clearly indicated that magnetic stimulation induced from early RMFs exposure significantly promoted neural regeneration of planarians. This stimulating effect is frequency and intensity dependent. Optimum effects were obtained when decapitated planarians were cultured at 20 °C, starved for 3 days before head-cutting, and treated with 6 Hz 0.02 T RMFs. At early regeneration stage, RMFs exposure eliminated edema around the wound and facilitated subsequent formation of blastema. It also accelerated cell proliferation and recovery of neuron functionality. Early RMFs exposure up-regulated expression of neural regeneration related proteins, EGR4 and Netrin 2, and mature nerve cell marker proteins, NSE and NPY. These results suggest that RMFs therapy produced early and significant benefit in central nervous regeneration, and should be clinically used at the early stage of neural regeneration, with appropriate optimal frequency and intensity.

Obligate anaerobic Salmonella typhimurium strain YB1 treatment on xenograft tumor in immunocompetent mouse model.

The present authors have previously reported a novel approach to genetically engineer Salmonella typhimurium for the medically important therapeutic strategy of using bacterial agents to target malignant tumors in a breast cancer tumor-bearing nude mouse model. However, studying an immunocompromised mouse model for cancer therapy is insufficient, as certain crucial information about the influence of the immune system may be missing. In the present study, inoculation of the Salmonella strain, YB1, into a colon cancer tumor-bearing immunocompetent mouse model was investigated. The present study determined the tumor targeting efficiency, antitumor potential, the effects of multiple treatments and the systemic toxicity. Intravenous inoculation of YB1 in BALB/c mice exhibited high antitumor effects and also greatly increased the tumor targeting ability and safety compared with the previously-reported nude mouse model. In addition, repeated administration of YB1 further enhanced this effect. Furthermore, no marked toxicity was observed with YB1 treatment, while the VNP20009 and SL7207 strains demonstrated certain adverse effects. The findings of the present study indicate that the YB1 strain is effective and safe in targeting a colon cancer tumor in an immunocompetent mouse model.

[High sensitivity conherent anti-stokes Raman scattering for linearly probing low concentration materials].

The authors made a theoretical analysis and experiment research on the relation of time-resolved coherent anti-Stokes Raman scattering (T-CARS) intensity and the sample concentrations in this paper. It was proved experimentally that the T-CARS intensity is quadratic at the concentration higher than 35%, but is linear with the sample concentration at the concentration lower than 20%, which fits with theoretical analysis. And the research results correct inaccurate previous perceptions, which is conducive to better interpretation and application of the CARS process. The linear relation between the intensity of the CARS with the sample concentration at low concentrations indicates that the CARS is allowed for direct and precise concentration measurements, therefore it will be of great importance in biology and biochemistry.

[Wooly-necked stork, a new bird record of China].

A new record species-the woolly-necked stork (Ciconia episcopus)-for China has been detected during a field survey of Shangri-La county, Diqing Tibetan autonomous prefecture, Yunnan province, June 10th, 2011. Ciconia episcopus is the least concern spices according to IUCN.

Is chytridiomycosis an emerging infectious disease in Asia?

The disease chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd), has caused dramatic amphibian population declines and extinctions in Australia, Central and North America, and Europe. Bd is associated with >200 species extinctions of amphibians, but not all species that become infected are susceptible to the disease. Specifically, Bd has rapidly emerged in some areas of the world, such as in Australia, USA, and throughout Central and South America, causing population and species collapse. The mechanism behind the rapid global emergence of the disease is poorly understood, in part due to an incomplete picture of the global distribution of Bd. At present, there is a considerable amount of geographic bias in survey effort for Bd, with Asia being the most neglected continent. To date, Bd surveys have been published for few Asian countries, and infected amphibians have been reported only from Indonesia, South Korea, China and Japan. Thus far, there have been no substantiated reports of enigmatic or suspected disease-caused population declines of the kind that has been attributed to Bd in other areas. In order to gain a more detailed picture of the distribution of Bd in Asia, we undertook a widespread, opportunistic survey of over 3,000 amphibians for Bd throughout Asia and adjoining Papua New Guinea. Survey sites spanned 15 countries, approximately 36° latitude, 111° longitude, and over 2000 m in elevation. Bd prevalence was very low throughout our survey area (2.35% overall) and infected animals were not clumped as would be expected in epizootic events. This suggests that Bd is either newly emerging in Asia, endemic at low prevalence, or that some other ecological factor is preventing Bd from fully invading Asian amphibians. The current observed pattern in Asia differs from that in many other parts of the world.

[A method of obtaining vibrational dephasing time of molecular multi-vibrational modes simultaneously].

In the present paper, the authors used the time-resolved coherent anti-Stokes Raman scattering (CARS) spectroscopy based on supercontinuum developed by ourselves to acquire simultaneously the molecular vibration spectrum and vibrational dephasing time of the molecular various vibrational modes. Using benzonitrile as the sample, the authors measured its vibrational relaxation processes at its five typical vibrational modes and obtained their vibrational dephasing time respectively. In the experiment, the authors also found the phenomenon that oscillations appear in the vibrational dephasing of plane bending vibration mode of benzene ring in benzonitrile, which was caused by superposition of the two adjacent normal vibrational modes excited simultaneously. After mixing benzonitrile with anhydrous ethanol, the authors also measured their vibrational dephasing time. This method is capable of monitoring the changes of the molecular characteristics and its micro-environment, therefore it will find widespread applications in biology, chemistry and materials science.

[Characterization of biocompatible CdTe/znte quantum dots and its application in cell labeling].

Water-soluble CdTe/ZnTe core-shell quantum dots (QDs) coated with L-cysteine were synthesized in low-temperature aqueous-phase one-pot approach. The authors measured the spectral characteristics of QDs at different pH in various buffer solutions and under different excitation laser powers. The primary results show that the absorption spectra of QDs approximately overlap and the fluorescence spectra peaks have no shift in different pH solution. The fluorescence intensity increased linearly with increasing pH. With the incubation time in borate buffer solution, the fluorescence intensity decreased a little. Under strong power laser, the QDs were photobleached rapidly. However, QDs are strongly anti-photobleaching under appropriate laser power (< 100 microW). Thus, such QDs have good biological stability and optical stability. By conjugating the QDs with transferrin protein and constructing the targeted fluorescent nanoparticles, the authors labelled the HeLa cell successfully. Photobleaching experiments in vivo show that microenvironment inside cells affect the stability and accelerate the photobleaching of QDs.

[Experimental study on mechanism of graft injury of small-for-size liver transplantation in miniature pigs].

OBJECTIVE: To elucidate the mechanisms of graft injury in small-for-size liver transplantation. METHODS: Animal models were established with skeletonized and denervated anatomic parahepatic dissection, hepatectomy and perfusion in situ. Chinese Bama miniature pigs were divided into three groups (n = 5): Group A, liver transplantation; Group B, partial liver transplantation with right hemi-liver graft and Group C, liver transplantation with right median and caudate lobe graft. Animals were followed for 7 days with regards to survival, dynamical portal venous pressure (PVP), portal blood flow (PBF) and graft histopathological examination. RESULTS: Animal survivals were as follows: Group A, 5/5, Group B, 5/5 and Group C, 1/5. PVP rose immediately after reperfusion. PVP in Group C peaked to 28.6 +/- 2.07 mm Hg. Portal blood flow (PBF) measured by CDFI showed that the index of PBF per gram liver tissue reached 3.56 +/- 0.11 ml x min(-1) x g(-1) at the first hour post-reperfusion in Group C. Hepatic morphological examination showed that severe pathological changes occurred in small-for-size grafts, including sinusoidal congestion, hemorrhage, hepatocytic ballooning change or necrosis, endothelial cell detachment, Disse's space widening or vanishing and significant apoptosis. CONCLUSION: Portal over perfusion and acute portal hypertension are the primary etiological mechanisms of graft injury in small-for-size liver transplantation.